Aim: The present study investigates the impact of routine therapy on the pain and disability of individuals with chronic mechanical low back pain referring to Rasha Rehabilitation Clinic in Tehran. Methods: This randomized clinical trial was conducted on 78 individuals referring to Rasha Rehabilitation Clinic in Tehran. Patients were divided into two groups: manual therapy and control. Visual analog scale (VAS) and Oswestry disability questionnaire were used before the intervention, after the intervention, and during the follow-up stages. Data were analyzed in SPSS-26 software. Results: The results revealed that the mean scores of pain (P<0.05, F=6.273) and disability (P<0.05, F=5.535) decreased in the manual therapy group in the post-test and follow-up stages compared to the pre-test stage in both experimental and control groups. Conclusion: Based on the results of the present study, manual therapy can reduce the pain and disability of individuals with chronic mechanical low back pain.