The PECL package does not come with the PHP tests, but they are available at Github. Download the driver source and there are tests in the tests/ directory. The driver uses PHPUnit for testing, which can be installed via PEAR. You must set error_reporting in php.ini to E_STRICT | E_ALL for all of the tests to pass. If you do not, you will get some failures that say the test was expecting a warning or error. To run the tests, make sure that there is a MongoDB server running locally on port 27017. Make sure you're in the main directory of the driver source you downloaded from Github. Run: Please report any failures or errors in the bugtracker. There may be skipped tests, these are normal and can be ignored. New tests are always welcome! Please feel free to contribute new tests of any type testing any functionality.