Background: This in vitro study investigated the angiogenesis and osteogenesis effects ofs h o c kwa v e s o n b o n e ma r r ow s t r oma l c e l l s ( BMS C s ) f r om h i p s wi t hosteonecrosis.Methods: BMSCs were harvested from the bone marrow cavity of the proximal femurin six patients with osteonecrosis of the femoral head. The specimens weredivided into four groups, the control, shockwave, shockwave plus nω-nitroL-arginine methyl ester (L-NAME) and a nitric oxide (NO) donor (NOC18)groups. The control group received no shockwaves and was used as the baseline. The shockwave group received 250 shockwave impulses at 14 Kv(equivalent to 0.18 mJ/mm2energy flux density). The shockwave plus LNAME group was pre-treated with L-NAME before receiving shockwaves.The NOC18 group received NOC18 after cell culture for 48 hours. The evaluations included cell proliferation (MTT) assay, alkaline phosphatase, realtime reverse transcriptase-polymerase chain reaction analysis of vesselendothelial growth factor (VEGF), bone morphogenic protein (BMP)-2,RUNX2 and osteocalcin mRNA expression and von Kossa stain for mineralized nodules.Results: The shockwave group showed significant increases in MTT, VEGF, alkalinephosphatase, BMP2, RUNX2 and osteocalcin mRNA expression and moremature mineralized nodules compared with the control. Pre-treatment withL-NAME significantly reduced the angiogenic and osteogenic effects ofextracorporeal shockwave therapy (ESWT) and the results were comparablewith the control. Administration of NOC18 significantly enhanced the angiogenesis and osteogenesis effects compared with the control and the resultswere comparable with the shockwave group.Conclusion: ESWT significantly enhanced the angiogenic and osteogenic effects ofBMSCs mediated through the NO pathway in hips with osteonecrosis. Theseinnovative findings, at least in part, explain some of the mechanism ofshockwaves in osteonecrosis of the hip.