A saliva drug test is designed to detect the presence of marijuana in saliva.  It involves using a swab to collect the saliva.   The swab pad is placed between the lower cheek and gum for about two minutes. Once saturated with saliva, the pad is then transferred to a collection container. Results will usually present themselves in minutes.

Saliva tests can only detect drugs usually up to 24 hours after use.  Therefore, it cannot detect past use and can easily be passed by abstaining for a day or two prior to the test.

While not as popular as a urine test, saliva tests are often used as part of a pre-employment drug screening process because they are non-invasive and inexpensive.