METHODS Single group repeated measures. OBJECTIVE To determine the effects of cessation and resumption of a hamstring muscle stretching protocol on knee range of motion (ROM). BACKGROUND It is generally accepted that stretching exercises result in an increase in ROM. The ability to maintain ROM once stretching has ceased and the ability to regain ROM after resumption of the stretching exercise is not well-known. METHODS Evaluated the effect of 6 weeks of static hamstring stretching, 4 weeks with cessation from stretching, and 6 weeks with resumption of stretching on knee ROM in 18 inactive college students (12 men, 6 women, mean age 21.0 years). The hamstring stretching consisted of 2 30-second stretches per day, 5 days per week. Knee ROM was measured before and after each of the above phases with an active knee extension test. RESULTS Mean knee ROM increased after the initial stretching period (143+/-11 to 152+/-9 degrees), decreased to baseline following the cessation period (145+/-8 degrees) and again increased following the resumption of stretching but was not different from the initial gains (154+/-10 degrees). Unlike the stretch limb, the control limb ROM did not change over the 4 measurement times. CONCLUSIONS There was no retention of knee ROM 4 weeks following a 6-week stretching protocol and a subsequent stretching period did not enhance the gain of knee ROM over the initial stretching period.