Platelet-rich plasma (PRP), a platelet concentrate made of autogenous blood, has been used to improve bone and soft tissue defect healing in recent years. The aim of this study was to assess the effect of PRP on articular cartilage defects in a rabbit model. Forty-eight osteochondral defects created in the femoropatellar groove were (a) left untreated, (b) treated with autogenous PRP in a poly-lactic-glycolic acid (PLGA), or (c) with PLGA alone. Platelets were enriched 5.12-fold compared to normal blood in the PRP. After four and 12 weeks, the explanted tissue specimens were assessed by macroscopic examination, micro-computed tomography, and histological evaluation. Macroscopic examination, micro-computed tomography and histology of the newly formed cartilage and bone in the defect differ significantly between the PRP-treated and the untreated groups, and stimulatory effect of PRP on osteochondral formation was observed. In conclusion, PRP in PLGA improves osteochondral healing in a rabbit model.