Objective To explore the feasibil ity and efficacy of percutaneous kyphoplasty (PKP) for the treatment of severe osteoporotic vertebral compression fracture (OVCF), and to assess the cl inical result of the PKP technique. Methods From May 2006 to October 2007, 12 patients with severe OVCF affecting more than 2/3 of the original vertebral body height were treated by using domestic PKP and percutaneous vertebroplasty (PVP) tool systems. There were 3 malesand 9 females, with the age of 56-82 years and a mean disease course of 4.2 months (1-49 months). Eleven thoracic vertebra and 4 lumbar vertebra suffered from severe vertebral compression fractures, which included 3 extremely severe thoracic OVCF. Four thoracic vertebra and 3 lumbar vertebra had not severe OVCF. There were 4 cases of single vertebral compression fracture, 6 cases of double fractures, and 2 cases of triple fractures. Only single side PKP and PVP were performed via extrapedicular approach in thoracic vertebra, and via transpedicular approach in lumbar spine under fluoroscopic control. Eight patients with severe thoracic compression fractures and 4 with severe lumbar fractures were treated by PKP. Four patients with relatively mild thoracic compression fractures and 3 with lumbar fractures were treated by PVP. Results The operation was successfully, 3 patients with extremely severe thoracic compression fractures received no intervention. The maximum expansion pressure of balloon was (1 068 ± 298) kPa, and the volume was (3.1 ± 1.2) mL during operation. The average operative time of PKP was (44.9 ± 10.6) minutes per vertebra, while the average operative time of PVP was (36.5 ± 6.8) minutes per vertebra. The average volume of injected bone cement was (2.5 ± 0.6) mL per thoracic vertebra, and (3.6 ± 1.2) mL per lumbar vertebra. The mean hospitalization time were (3.7 ± 1.6) days. Twelve cases were followed up 5-18 months (mean 8.6 months). The visual analogue scale scoreswere (2.35 ± 0.61) points 2 days after operation and (2.89 ± 1.07) points at last follow-up, there were statistically significant differences when compared with before operation (8.27 ± 1.36) points (P lt; 0.01). Extravertebral leakage of the bone cement into the paravertebral tissue and/or disc occurred in 6 patients (9 vertebra) without significant symptom. Conclusion One side approach PKP is a safe and effective technique for treatment of severe OVCF with markedly rel ief of pain.