diff --git a/changelog_unreleased/scss/18471.md b/changelog_unreleased/scss/18471.md
new file mode 100644
index 000000000..f4ff3d42c
--- /dev/null
+++ b/changelog_unreleased/scss/18471.md
@@ -0,0 +1,15 @@
+#### Prevent trailing comma in `if()` function (#18471 by @kovsu)
+
+<!-- prettier-ignore -->
+```scss
+// Input
+$value: if(sass(false): 1; else: -1);
+
+// Prettier stable
+$value: if(
+  sass(false): 1; else: -1,
+);
+
+// Prettier main
+$value: if(sass(false): 1; else: -1);
+```
diff --git a/src/language-css/utilities/index.js b/src/language-css/utilities/index.js
index b2354bdca..6477cb24a 100644
--- a/src/language-css/utilities/index.js
+++ b/src/language-css/utilities/index.js
@@ -261,6 +261,18 @@ function isSCSSMapItemNode(path, options) {
     return false;
   }
 
+  const parentNode = path.parent;
+
+  // Don't treat SCSS if function arguments as maps (`if(sass(condition): value; else: value)`)
+  // https://sass-lang.com/documentation/breaking-changes/if-function/
+  if (
+    parentNode &&
+    parentNode.type === "value-func" &&
+    parentNode.value === "if"
+  ) {
+    return false;
+  }
+
   const parentParentNode = path.grandparent;
 
   // Check open parens contain key/value pair (i.e. `(key: value)` and `(key: (value, other-value)`)
diff --git a/tests/format/scss/function/18465.scss b/tests/format/scss/function/18465.scss
new file mode 100644
index 000000000..426305a74
--- /dev/null
+++ b/tests/format/scss/function/18465.scss
@@ -0,0 +1 @@
+$value: if(sass(false): 1; else: -1);
diff --git a/tests/format/scss/function/__snapshots__/format.test.js.snap b/tests/format/scss/function/__snapshots__/format.test.js.snap
index 78c6b2c6b..381e9685f 100644
--- a/tests/format/scss/function/__snapshots__/format.test.js.snap
+++ b/tests/format/scss/function/__snapshots__/format.test.js.snap
@@ -210,6 +210,36 @@ div {
 ================================================================================
 `;
 
+exports[`18465.scss - {"trailingComma":"es5"} format 1`] = `
+====================================options=====================================
+parsers: ["scss"]
+printWidth: 80
+trailingComma: "es5"
+                                                                                | printWidth
+=====================================input======================================
+$value: if(sass(false): 1; else: -1);
+
+=====================================output=====================================
+$value: if(sass(false): 1; else: -1);
+
+================================================================================
+`;
+
+exports[`18465.scss - {"trailingComma":"none"} format 1`] = `
+====================================options=====================================
+parsers: ["scss"]
+printWidth: 80
+trailingComma: "none"
+                                                                                | printWidth
+=====================================input======================================
+$value: if(sass(false): 1; else: -1);
+
+=====================================output=====================================
+$value: if(sass(false): 1; else: -1);
+
+================================================================================
+`;
+
 exports[`arbitrary-arguments.scss - {"trailingComma":"es5"} format 1`] = `
 ====================================options=====================================
 parsers: ["scss"]