Fifty-four patients diagnosed with chronic low back pain were randomized to undergo an isostretching exercise program or a control group (no treatment; waiting listed for physical therapy). Primary outcomes of interest included pain and function were measured using the visual analogue scale (VAS) and the the Roland-Morris Disability Questionnaire (RMDQ), respectively. Additional outcomes included quality of life measured using the Short Form 36 (SF-36) survey and associated sub-scores (i.e. functional capacity, physical aspects, pain, general health status, mental health, emotional aspects, social aspects, and vitality). Furthermore, patient and evaluator satisfaction, as well as number of diclofenac pills consumed, were also evaluated. All outcomes were measured at 20-days and 45-days follow-up. Results revealed that in the isostretching exercise group, VAS mean and RMDQ values both statistically significantly improved over time (p<0.001 for both), but not in the control group (p>0.05 for both). The improvement over time in VAS and mean RMDQ scores was statistically significantly greater in the isostretching group (p=0.003; p=0.026). The number of diclofenac pills consumed were also statistically significantly less in the isostretching group at 20-days and 45 days follow-up compared to the control (p=0.03 for both). For quality of life outcomes, the improvement over time in functional capacity, physical aspects and general health status subscores was statistically significantly greater in the isostretching group (p=0.012; p=0.011; p=0.006, respectively); however, all other sub-scores were not statistically significant (p>0.05). Finally, patient satisfaction at both 20 and 45 days follow-up was statistically significantly better in the isostretching group compared to the control group (p<0.001 for both). The same pattern was observed for the evaluator satisfaction.