Purpose: Growth factors (GFs) and neurotrophins can decelerate retinal degeneration. This study aimed to investigate the safety, efficacy and durability of subtenon injections of autologous platelet-rich plasma (aPRP) which is a rich source of GFs in retinitis pigmentosa (RP) patients. Methods: 154 eyes of 77 RP patients with various degrees of narrowed visual field were investigated in this study. Each patient received three injections with 4-week intervals and followed for at least 12 months. The examinations and the tests were obtained before the injection, 1 month after the third injection and every 3 months during the study. The primary aim was to evaluate the effects of aPRP on visual acuity (VA) and visual functions, the second aim was to estimate the duration of the therapy effect and the need for additional aPRP injection. Results: Median age of the 77 RP patients was 35.2 ± 13.9 years. All of the eyes received 3 monthly bilateral subtenon aPRP injections. Of these patients 26 received an additional one, 12 received additional two and 1 patient received additional 3 injections with 3-month interval. There were no significant ocular or systemic side effects. The mean baseline VA was 0.22 ± 0.18 Snellen lines. It improved to 0.31 ± 0.19 following three aPRP injections, which was statistically significant. At the end of the study period, the mean VA was 0.27 ± 0.22 Snellen lines. Conclusion: The subtenon injection of aPRP might be an effective therapy and might have a positive influence in the preservation of visual functions and visual acuity of RP patients.