INTRODUCTION: Intractable plantar fasciitis can be a difficult condition to treat. Early results of platelet rich plasma (PRP) injection have been promising. We compared PRP to traditional cortisone injection in the treatment of chronic cases of plantar fasciitis resistant to traditional nonoperative management. The aim of the study was to compare the efficacy of PRP to that of Steroid at 3, 6 and 12 months after injection. METHODS: 60 heels with intractable plantar fasciitis who had failed conservative treatment were randomised to receive either PRP or Steroid injection. All patients were assessed with the Roles-Maudsley (RM) Score, Visual Analogue Score (VAS) for pain and the American Orthopaedic Foot and Ankle Society (AOFAS) score. Data was collected prospectively on the cohort, pre-treatment, at 3, 6 and 12 months post injection and the results were compared. RESULTS: Pre-injection, the two groups were well matched with no statistically significant difference. At 3 months, all three outcome scores had significantly improved from their pretreatment level in both groups. The scores in the Steroid arm were marginally better than in the PRP arm, but this difference was not statistically significant. At 6 months, there was no statistically significant difference between the two groups, though there was a trend for the PRP scores to become better than the Steroid scores. At 12 months, the RM, VAS and AOFAS scores in the PRP arm (1.9, 3.3 and 88.5) were significantly better than the Steroid arm (2.6, 5.3 and 75) with P values of .013, .028 and .033, respectively. CONCLUSIONS: PRP is as effective as Steroid injection at achieving symptom relief at 3 and 6 months after injection, for the treatment of plantar fasciitis, but unlike Steroid, its effect does not wear off with time. At 12 months, PRP is significantly more effective than Steroid, making it better and more durable than cortisone injection.