diff --git a/README.md b/README.md
index 85c7766e8..4b79426ce 100644
--- a/README.md
+++ b/README.md
@@ -397,6 +397,7 @@ GuardDog's behavior can be customized using environment variables:
 |---------------------|-------------|---------------|
 | `GUARDDOG_PARALLELISM` | Number of threads to use for parallel processing | Number of CPUs available |
 | `GUARDDOG_VERIFY_EXHAUSTIVE_DEPENDENCIES` | Analyze all possible versions of dependencies (`true`/`false`) | `false` |
+| `GUARDDOG_NPM_INCLUDE_DEV_DEPENDENCIES` | Include `devDependencies` when scanning npm `package.json` files (`true`/`false`) | `false` |
 | `GUARDDOG_TOP_PACKAGES_CACHE_LOCATION` | Location of the top packages cache directory | `guarddog/analyzer/metadata/resources` |
 | `GUARDDOG_YARA_EXT_EXCLUDE` | Comma-separated list of file extensions to exclude from YARA scanning | `ini,md,rst,txt,lock,json,yaml,yml,toml,xml,html,csv,sql,pdf,doc,docx,ppt,pptx,xls,xlsx,odt,changelog,readme,makefile,dockerfile,pkg-info,d.ts` |
 
diff --git a/guarddog/scanners/npm_project_scanner.py b/guarddog/scanners/npm_project_scanner.py
index 7cd88d0dd..725c32ccc 100644
--- a/guarddog/scanners/npm_project_scanner.py
+++ b/guarddog/scanners/npm_project_scanner.py
@@ -9,7 +9,10 @@
 
 from guarddog.scanners.npm_package_scanner import NPMPackageScanner
 from guarddog.scanners.scanner import Dependency, DependencyVersion, ProjectScanner
-from guarddog.utils.config import VERIFY_EXHAUSTIVE_DEPENDENCIES
+from guarddog.utils.config import (
+    NPM_INCLUDE_DEV_DEPENDENCIES,
+    VERIFY_EXHAUSTIVE_DEPENDENCIES,
+)
 
 log = logging.getLogger("guarddog")
 
@@ -86,12 +89,15 @@ def find_all_versions(package_name: str) -> set[str]:
             return versions
 
         merged = {}  # type: dict[str, set[str]]
-        for package, selector in list(dependencies_attr.items()) + list(
-            dev_dependencies_attr.items()
-        ):
-            if package not in merged:
-                merged[package] = set()
-            merged[package].add(selector)
+        dependency_groups = [dependencies_attr.items()]
+        if NPM_INCLUDE_DEV_DEPENDENCIES:
+            dependency_groups.append(dev_dependencies_attr.items())
+
+        for dependency_group in dependency_groups:
+            for package, selector in dependency_group:
+                if package not in merged:
+                    merged[package] = set()
+                merged[package].add(selector)
 
         dependencies: List[Dependency] = []
         for package, all_selectors in merged.items():
diff --git a/guarddog/utils/config.py b/guarddog/utils/config.py
index 1824cf11b..02a20a7e9 100644
--- a/guarddog/utils/config.py
+++ b/guarddog/utils/config.py
@@ -18,6 +18,16 @@
     os.environ.get("GUARDDOG_VERIFY_EXHAUSTIVE_DEPENDENCIES", "false").lower() == "true"
 )
 
+"""
+This flag specifies if npm devDependencies should be included in project scans
+- True: dependencies and devDependencies are analyzed
+- False [default]: Only dependencies are analyzed
+"""
+NPM_INCLUDE_DEV_DEPENDENCIES: bool = (
+    os.environ.get("GUARDDOG_NPM_INCLUDE_DEV_DEPENDENCIES", "false").lower()
+    == "true"
+)
+
 """
 This parameter specifies the location of the top packages cache
 - Default: guarddog/analyzer/metadata/resources
diff --git a/tests/core/test_npm_requirements_scanner.py b/tests/core/test_npm_requirements_scanner.py
index f722baa18..a5a0b087e 100644
--- a/tests/core/test_npm_requirements_scanner.py
+++ b/tests/core/test_npm_requirements_scanner.py
@@ -1,6 +1,7 @@
 import os
 import pathlib
 
+import guarddog.scanners.npm_project_scanner as npm_project_scanner
 from guarddog.scanners.npm_project_scanner import NPMRequirementsScanner
 
 
@@ -55,3 +56,45 @@ def test_npm_requirements_scanner_github():
     )
     assert lookup is not None
     assert "https://github.com/expressjs/cors.git" in lookup.versions
+
+
+def test_npm_requirements_scanner_excludes_dev_dependencies_by_default(monkeypatch):
+    monkeypatch.setattr(
+        npm_project_scanner, "NPM_INCLUDE_DEV_DEPENDENCIES", False
+    )
+    scanner = NPMRequirementsScanner()
+    result = scanner.parse_requirements("""
+    {
+        "dependencies": {
+            "express": "4.x"
+        },
+        "devDependencies": {
+            "joi": "17.6"
+        }
+    }
+    """)
+
+    dependency_names = {dependency.name for dependency in result}
+    assert "express" in dependency_names
+    assert "joi" not in dependency_names
+
+
+def test_npm_requirements_scanner_includes_dev_dependencies_when_enabled(monkeypatch):
+    monkeypatch.setattr(
+        npm_project_scanner, "NPM_INCLUDE_DEV_DEPENDENCIES", True
+    )
+    scanner = NPMRequirementsScanner()
+    result = scanner.parse_requirements("""
+    {
+        "dependencies": {
+            "express": "4.x"
+        },
+        "devDependencies": {
+            "joi": "17.6"
+        }
+    }
+    """)
+
+    dependency_names = {dependency.name for dependency in result}
+    assert "express" in dependency_names
+    assert "joi" in dependency_names