To examine the absolute reliability of five methods for estimating hamstring flexibility in professional futsal players.Absolute reliability laboratory study (k=4).A total of 46 male futsal players (172.9±4.5cm; 69.7±7.5Kg) completed the study. All participants performed each measurement test twice in a randomized order on four different occasions. Absolute reliability was examined through typical percentage error, percentage change in the mean and intraclass correlations (ICC) as well as their respective confidence limits.The findings showed high reliability for the sit and reach test (SRT) (4.48% typical error; 0.84% change in the mean, 0.95 ICC), toe touch test (TT) (5.89% typical error; 2.31% change in the mean, 0.89 ICC) and back-saver sit and reach test (BSSR) (3.73% typical error; 0.51% change in the mean, 0.97 ICC) compared to the passive straight leg raise test (PSLR) (7.6% typical error; 8.86% change in the mean, 0.77 ICC) and modified sit and reach test (MSR) (11.87% typical error; 7.64% change in the mean, 0.84 ICC) which showed moderate reliability.An observed change larger than 6.72%, 7.55% and 5.59% for baseline SRT, TT and BSSR scores respectively would indicate that a real improvement in hamstring flexibility has occurred. In addition, the clinical reliability of PSLR and MSR are questioned and should be re-evaluated in future research studies.