diff --git a/.changeset/fix-db-env-var-loading.md b/.changeset/fix-db-env-var-loading.md
new file mode 100644
index 000000000000..b5c2c51ed112
--- /dev/null
+++ b/.changeset/fix-db-env-var-loading.md
@@ -0,0 +1,5 @@
+---
+'@astrojs/db': patch
+---
+
+Fixed `ASTRO_DATABASE_FILE` environment variable not being read from `.env` files during build. The `databaseFileEnvDefined()` function now uses `getAstroEnv()` which correctly loads `ASTRO_`-prefixed env vars, instead of Vite's `loadEnv()` which defaults to only loading `VITE_`-prefixed variables.
diff --git a/packages/db/src/core/integration/index.ts b/packages/db/src/core/integration/index.ts
index 3e4cca65d990..c0a748f95547 100644
--- a/packages/db/src/core/integration/index.ts
+++ b/packages/db/src/core/integration/index.ts
@@ -7,7 +7,6 @@ import colors from 'piccolore';
 import {
 	createServer,
 	type HotPayload,
-	loadEnv,
 	mergeConfig,
 	type RunnableDevEnvironment,
 	type UserConfig,
@@ -20,7 +19,7 @@ import { CONFIG_FILE_NAMES, DB_PATH, VIRTUAL_MODULE_ID } from '../consts.js';
 import { EXEC_DEFAULT_EXPORT_ERROR, EXEC_ERROR } from '../errors.js';
 import { resolveDbConfig } from '../load-file.js';
 import { SEED_DEV_FILE_NAME } from '../queries.js';
-import { getDbDirectoryUrl, getRemoteDatabaseInfo, type VitePlugin } from '../utils.js';
+import { getAstroEnv, getDbDirectoryUrl, getRemoteDatabaseInfo, type VitePlugin } from '../utils.js';
 import { fileURLIntegration } from './file-url.js';
 import { getDtsContent } from './typegen.js';
 import {
@@ -209,7 +208,7 @@ function astroDBIntegration(options?: AstroDBConfig): AstroIntegration {
 }
 
 function databaseFileEnvDefined() {
-	const env = loadEnv('', process.cwd());
+	const env = getAstroEnv();
 	return env.ASTRO_DATABASE_FILE != null || process.env.ASTRO_DATABASE_FILE != null;
 }