In recent years, biologic therapies such as platelet-rich plasma (PRP) have gained prominence in multiple orthopedics degenerative tendinopathy and ligamental pathology. This research aimed to assess the clinical effectiveness of autologous platelet-rich plasma injection in cases of recalcitrant plantar fasciitis (RPF) over a long period.A prospective observational study was performed on RPF that did not experience pain relief after three months of conservative therapy. Under sterile conditions, inject approximately 3ml of platelet-rich plasma mixed with 0.5ml lignocaine into the maximum tender point of the heel. Visual Analogue Score for Pain, the American Orthopedics Foot, and Ankle Society (AOFAS) Ankle, and Hind Foot Score at one month, three months, six months, one year, and two years after injection.A total of 60 patients of RPF which 23 (38.33%) were male, and the rest 37 (61.66%) were female. The mean age was 45 ± 7.25 and the mean duration of symptoms was 7.4 ± 2.1months. The mean VAS score was 7.92 ± 1.2 at pre-injection, was progressively reduced post-injection to 5.61 ± 1.56 at one month, 3.1 ± .83 at three months, and 2.4 ± .68 at six months and remained at low level 2.5 ± .92 at one year and 2.7 ± .56 at two years. The mean AOFAS score was 56.92 ± 13.24 at pre-injection, was progressively increased post-injection to 66.41± 10.26 at one month, 78.31 ± 12.64 at three months, and 90.54 ± 10.71 at six months and remained at a low level 89.24 ± 8.92 at one year and 87.54 ±10.56 at two years. Mean VAS and AOFAS scores showed statistically significant pain reduction and functional improvements at successive follow-ups till 6month (p<.05); the improvement remained stable and did not change significantly until the last appointment at 2year follow-up (p > 0.05).The outcomes of autologous PRP injection in recalcitrant plantar fasciitis are reliable, stable, and predictable in both long- and short-term follow-up. PRP injection is safer and not associated with serious complications as in the case of steroid injection.