BACKGROUND Chondral injuries are commonly related to poor clinical outcome, but recent data showed some improvements in function and pain after hip arthroscopy. Cell-based therapies represent an appealing alternative strategy for cartilage regeneration, and interesting results have been recently reported after intra-articular injections of mesenchymal stem cells (MSCs). The results of hip arthroscopy for femoroacetabular impingement (FAI) and intra-articular injections of autologous expanded bone marrow - MSCs (BM-MSCs) are reported in this retrospective study. MATERIALS AND METHODS Twenty patients (29 hips) received hip arthroscopy for FAI and focal cartilage injuries or mild to moderate osteoarthrosis (OA). Three intra-articular injections of 20×106 BM-MSCs were injected from 4 to 6 weeks postoperative. The modified Harris Hip score (mHHS), the WOMAC score, the VAIL score and VAS score were administered to all patients. RESULTS The mean age of the patients was 51.8 years, and the mean follow-up was 24 months. The median preoperative mHHS, WOMAC and VAIL scores were 64.3, 73 and 56.5 respectively, and they increased to 91, 97 and 83 at final follow up (p<0.05). The VAS score also improved from a median of 6 to 2. Four patients received a THA (13% of the hips) at the median of 9 months post intervention (range 6-36 months). Six patients referred pain after the injection of MSCs, which improved with oral pain killers. No major complications were reported. CONCLUSION BM-MSCc injections in combination with hip arthroscopy may improve the quality of life and functional score in patient with FAI and cartilage injuries which are still not candidate to a THA. LEVEL OF EVIDENCE IV case series.