Introduction. Chronic plantar fasciitis is the most frequent cause of plantar talalgia. The treatment in cases refractory to conservative measures is controversial. Objectives. To demonstrate clinical efficacy of a protocol of 2 infiltrations with platelet-rich plasma (PRP) in chronic talalgias in plantar fasciitis compared to another one of 2 infiltrations with corticosteroids. Material and methods. We conducted a quasi-experimental, non-randomized, controlled, non-blinded, analytical study that evaluated the effectiveness of 2 infiltrations of PRP in chronic plantar fasciitis refractory to conservative treatment. Clinical results were assessed by EVA, AOFAS, SF12 questionnaire and Roles and Maudsley scale after 6 years of treatment. Results. There were no complications derived from the treatment in any patient. In the group treated with PRP the clinical results were clearly better and more lasting: the punctuation of the scale AOFAS improved from 47,05 to 92,1 after 6 months; and the EVA improved from 8,25 to 2,25 after 77,7 months. In the group treated with corticoides the scale AOFAS improved from 50,85 to 49,75 points after 6 months; and the EVA improved from 7,97 to 6,77 after 77,7 months.Conclusions. Percutaneous infiltrations of PRP are an effective and safe therapeutic option in the treatment of chronic plantar fasciitis, maintaining its long-term results.