diff --git a/src/resolvers/convert-arg.ts b/src/resolvers/convert-arg.ts
new file mode 100644
index 000000000..2af9c80c7
--- /dev/null
+++ b/src/resolvers/convert-arg.ts
@@ -0,0 +1,99 @@
+import { ArgParamMetadata, ClassMetadata } from "../metadata/definitions";
+import { convertToType } from "../helpers/types";
+import { ArgsDictionary } from "../interfaces";
+import { ClassType } from "../interfaces/ClassType";
+import { getMetadataStorage } from "../metadata/getMetadataStorage";
+
+interface InputTypeField {
+  name: string;
+  fields?: InputTypeClass;
+  isArray?: boolean;
+}
+
+interface InputTypeClass {
+  target: ClassType;
+  fields: InputTypeField[];
+}
+
+const generatedTrees = new Map<ClassType, InputTypeClass | null>();
+
+function getInputType(target: ClassType): ClassMetadata | undefined {
+  return getMetadataStorage().inputTypes.find(t => t.target === target);
+}
+
+function generateTree(param: ArgParamMetadata): InputTypeClass | null {
+  const target = param.getType() as ClassType;
+
+  if (generatedTrees.has(target)) {
+    return generatedTrees.get(target) as InputTypeClass;
+  }
+
+  const inputType = getInputType(target);
+
+  if (!inputType) {
+    generatedTrees.set(target, null);
+
+    return null;
+  }
+
+  const generate = (meta: ClassMetadata): InputTypeClass => {
+    const value: InputTypeClass = {
+      target: meta.target as ClassType,
+      fields: (meta.fields || []).map(field => {
+        const fieldInputType = getInputType(field.getType() as ClassType);
+
+        return {
+          name: field.name,
+          fields: fieldInputType ? generate(fieldInputType) : undefined,
+          isArray: field.typeOptions.array === true,
+        };
+      }),
+    };
+
+    const superPrototype = Object.getPrototypeOf(meta.target);
+    if (superPrototype) {
+      const superInputType = getInputType(superPrototype);
+      if (superInputType) {
+        value.fields = value.fields.concat(generate(superInputType).fields);
+      }
+    }
+
+    return value;
+  };
+
+  const tree = generate(inputType);
+
+  generatedTrees.set(target, tree);
+
+  return tree;
+}
+
+function convertToInput(tree: InputTypeClass, data?: any) {
+  const input = new tree.target();
+
+  tree.fields.forEach(field => {
+    if (typeof field.fields !== "undefined") {
+      const siblings = field.fields;
+
+      if (field.isArray) {
+        input[field.name] = (data[field.name] || []).map((value: any) =>
+          convertToInput(siblings, value),
+        );
+      } else {
+        input[field.name] = convertToInput(siblings, data[field.name]);
+      }
+    } else {
+      input[field.name] = data[field.name];
+    }
+  });
+
+  return input;
+}
+
+export function convertToArg(param: ArgParamMetadata, args: ArgsDictionary) {
+  const tree = generateTree(param);
+
+  return tree
+    ? convertToInput(tree, args[param.name])
+    : convertToType(param.getType(), args[param.name]);
+}
diff --git a/src/resolvers/helpers.ts b/src/resolvers/helpers.ts
index c21eb9728..158997561 100644
--- a/src/resolvers/helpers.ts
+++ b/src/resolvers/helpers.ts
@@ -1,6 +1,5 @@
 import { PubSubEngine } from "graphql-subscriptions";
 import { ValidatorOptions } from "class-validator";
-
 import { ParamMetadata } from "../metadata/definitions";
 import { convertToType } from "../helpers/types";
 import { validateArg } from "./validate-arg";
@@ -8,6 +7,7 @@ import { ResolverData, AuthChecker, AuthMode } from "../interfaces";
 import { Middleware, MiddlewareFn, MiddlewareClass } from "../interfaces/Middleware";
 import { IOCContainer } from "../utils/container";
 import { AuthMiddleware } from "../helpers/auth-middleware";
+import { convertToArg } from "./convert-arg";
 
 export async function getParams(
   params: ParamMetadata[],
@@ -28,7 +28,7 @@ export async function getParams(
             );
           case "arg":
             return await validateArg(
-              convertToType(paramInfo.getType(), resolverData.args[paramInfo.name]),
+              convertToArg(paramInfo, resolverData.args),
               globalValidate,
               paramInfo.validate,
             );
diff --git a/tests/functional/resolvers.ts b/tests/functional/resolvers.ts
index 9af4fc27f..c0553f7e0 100644
--- a/tests/functional/resolvers.ts
+++ b/tests/functional/resolvers.ts
@@ -2053,4 +2053,83 @@ describe("Resolvers", () => {
       expect(thisVar).toBeInstanceOf(childResolver);
     });
   });
+
+  it("nested inputs", async () => {
+    getMetadataStorage().clear();
+
+    @InputType()
+    class NestedBaseInput {
+      @Field()
+      nestedBaseInputField: string;
+    }
+
+    @InputType()
+    class SampleBaseInput {
+      @Field()
+      baseInputField: string;
+
+      @Field()
+      nestedBaseInputField: NestedBaseInput;
+
+      @Field(() => [NestedBaseInput])
+      nestedBaseInputFieldArray: NestedBaseInput[];
+    }
+
+    @InputType()
+    class NestedInput {
+      @Field()
+      inputField: string;
+    }
+
+    @InputType()
+    class SampleInput extends SampleBaseInput {
+      @Field()
+      nested: NestedInput;
+
+      @Field(() => [NestedInput])
+      nestedArray: NestedInput[];
+    }
+
+    let input: SampleInput | undefined;
+
+    @Resolver()
+    class SampleResolver {
+      @Query()
+      sampleQuery(@Arg("input") i: SampleInput): string {
+        input = i;
+
+        return "sampleQuery";
+      }
+    }
+
+    const schema = await buildSchema({ resolvers: [SampleResolver] });
+
+    const query = `query {
+        sampleQuery(input: {
+          baseInputField: "base input field"
+          nestedBaseInputField: { nestedBaseInputField: "nested base input field value" }
+          nestedBaseInputFieldArray: [{ nestedBaseInputField: "nested base input field value" }]
+          nested: { inputField: "value 1" }
+          nestedArray: [{ inputField: "value 2" }]
+        })
+      }`;
+
+    await graphql(schema, query);
+
+    expect(input).toBeInstanceOf(SampleInput);
+    expect((input as SampleInput).nested).toBeInstanceOf(NestedInput);
+    expect((input as SampleInput).baseInputField).toBe("base input field");
+    expect((input as SampleInput).nestedBaseInputField).toBeInstanceOf(NestedBaseInput);
+    expect((input as SampleInput).nestedBaseInputField.nestedBaseInputField).toBe(
+      "nested base input field value",
+    );
+    expect((input as SampleInput).nestedBaseInputFieldArray).toHaveLength(1);
+    expect((input as SampleInput).nestedBaseInputFieldArray[0]).toBeInstanceOf(NestedBaseInput);
+    expect((input as SampleInput).nestedBaseInputFieldArray[0].nestedBaseInputField).toBe(
+      "nested base input field value",
+    );
+    expect((input as SampleInput).nestedArray).toHaveLength(1);
+    expect((input as SampleInput).nestedArray[0]).toBeInstanceOf(NestedInput);
+    expect((input as SampleInput).nestedArray[0].inputField).toBe("value 2");
+  });
 });