diff --git a/test/_input/pnm/test.pbm b/test/_input/pnm/test.pbm
new file mode 100644
index 0000000..73c7a5b
--- /dev/null
+++ b/test/_input/pnm/test.pbm
@@ -0,0 +1,10 @@
+P1
+24 # PBM example
+7
+0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
+0 1 1 1 1 0 0 1 1 1 1 0 0 1 1 1 1 0 0 1 1 1 1 0
+0 1 0 0 0 0 0 1 0 0 0 0 0 1 0 0 0 0 0 1 0 0 1 0
+0 1 1 1 0 0 0 1 1 1 0 0 0 1 1 1 0 0 0 1 1 1 1 0
+0 1 0 0 0 0 0 1 0 0 0 0 0 1 0 0 0 0 0 1 0 0 0 0
+0 1 0 0 0 0 0 1 1 1 1 0 0 1 1 1 1 0 0 1 0 0 0 0
+0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
\ No newline at end of file
diff --git a/test/_input/pnm/test.pgm b/test/_input/pnm/test.pgm
new file mode 100644
index 0000000..ba47572
--- /dev/null
+++ b/test/_input/pnm/test.pgm
@@ -0,0 +1,10 @@
+P2
+24 7
+15
+0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
+0  3  3  3  3  0  0  7  7  7  7  0  0 11 11 11 11  0  0 15 15 15 15  0
+0  3  0  0  0  0  0  7  0  0  0  0  0 11  0  0  0  0  0 15  0  0 15  0
+0  3  3  3  0  0  0  7  7  7  0  0  0 11 11 11  0  0  0 15 15 15 15  0
+0  3  0  0  0  0  0  7  0  0  0  0  0 11  0  0  0  0  0 15  0  0  0  0
+0  3  0  0  0  0  0  7  7  7  7  0  0 11 11 11 11  0  0 15  0  0  0  0
+0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
\ No newline at end of file
diff --git a/test/_input/pnm/test.ppm b/test/_input/pnm/test.ppm
new file mode 100644
index 0000000..ecd1b91
--- /dev/null
+++ b/test/_input/pnm/test.ppm
@@ -0,0 +1,8 @@
+P3
+# example from the man page
+4 4
+15
+ 0  0  0    0  0  0    0  0  0   15  0 15
+ 0  0  0    0 15  7    0  0  0    0  0  0
+ 0  0  0    0  0  0    0 15  7    0  0  0
+15  0 15    0  0  0    0  0  0    0  0  0
\ No newline at end of file
diff --git a/test/_input/pnm/z00n2c08.pnm b/test/_input/pnm/z00n2c08.pnm
new file mode 100644
index 0000000..55da3c5
Binary files /dev/null and b/test/_input/pnm/z00n2c08.pnm differ
diff --git a/test/_utils/test-section.ts b/test/_utils/test-section.ts
index ff5960a..2b21cfc 100644
--- a/test/_utils/test-section.ts
+++ b/test/_utils/test-section.ts
@@ -12,6 +12,7 @@ export enum TestSection {
   ico,
   jpeg,
   png,
+  pnm,
   tiff,
   tga,
   transform,
diff --git a/test/_utils/test-utils.ts b/test/_utils/test-utils.ts
index ed708f1..dc3260d 100644
--- a/test/_utils/test-utils.ts
+++ b/test/_utils/test-utils.ts
@@ -47,6 +47,8 @@ export abstract class TestUtils {
         return 'jpg';
       case TestSection.png:
         return 'png';
+      case TestSection.pnm:
+        return 'pnm';
       case TestSection.tiff:
         return 'tiff';
       case TestSection.tga:
diff --git a/test/format/format.pnm.test.ts b/test/format/format.pnm.test.ts
new file mode 100644
index 0000000..f6bdc45
--- /dev/null
+++ b/test/format/format.pnm.test.ts
@@ -0,0 +1,38 @@
+/** @format */
+
+import { encodePng, PnmDecoder } from '../../src';
+import { TestFolder } from '../_utils/test-folder';
+import { TestSection } from '../_utils/test-section';
+import { TestUtils } from '../_utils/test-utils';
+
+describe('Format: PNM', () => {
+  const resFiles = TestUtils.listFiles(TestFolder.input, TestSection.pnm);
+
+  for (const file of resFiles) {
+    test(`pnm ${file.fileName}`, () => {
+      const input = TestUtils.readFromFilePath(file.path);
+      const decoder = new PnmDecoder();
+
+      const isValidFile = decoder.isValidFile(input);
+      expect(isValidFile).toBeTruthy();
+
+      const image = decoder.decode({
+        bytes: input,
+      });
+      expect(image).toBeDefined();
+      if (image === undefined) {
+        return;
+      }
+
+      const output = encodePng({
+        image: image,
+      });
+      TestUtils.writeToFile(
+        TestFolder.output,
+        TestSection.pnm,
+        `${file.fileName}.png`,
+        output
+      );
+    });
+  }
+});