The purpose of this study was to 1) compare two commonly practiced stretching techniques to determine which is most effective for improving hip range of motion, and 2) evaluate the effect of these techniques on gait economy. Seven asymptomatic males, 18-22 years of age, served as subjects. Goniometric measurements of hip range of motion (ROM) and gait economy, as measured by submaximal oxygen consumption of walking and running on a treadmill, were taken before and after each of the two stretching procedures, (a) static stretching, and (b) soft tissue mobilization with proprioceptive neuromuscular facilitation (STM/PNF). Static stretching procedures resulted in significant improvements in ROM for hip extension (p < 0.01) and hip flexion (p < 0.01). The STM/PNF also resulted in significant improvements in hip extension ROM (p < 0.01) and hip flexion ROM (p < 0.05). There was a significant improvement in gait economy at 40% VO2max (p < 0.05), at 60% VO2max (p < 0.05), and at 80% VO2max (p < 0.01) following the static stretching procedure. The STM/PNF procedure improved gait economy only at one workload, 60% of VO2max (p < 0.05). These results suggest that a single bout of static stretching or STM/PNF was effective for improving hip ROM but static stretching was more effective for improving gait economy in young, asymptomatic males. J Orthop Sports Phys Ther 1989;10(9):350-357.