There is an absence of literature pertaining to the reliability of core muscular endurance tests. The purpose of this study was to assess the test-retest and interrater reliability of four core muscular endurance tests. Participants were physically active, college students. Data were gathered during three trials for each core test. Participants were timed by two test administrators (raters) until the participant could no longer hold the test position. Test-retest reliability values ranged from 0.57–0.85 for all three trials, and from 0.80–0.89 for the latter two trials. Interrater reliability values ranged from 0.99–1.00 for all three trials of all four tests. Although the participants were not athletes, we were able to demonstrate good test-retest and interrater reliability for the core muscular endurance tests assessed.