PURPOSE: The objectives of this study were to assess pain relief according to the time after kyphoplasty and to evaluate the factors affecting pain relief after kyphoplasty in the treatment of a single-level osteoporotic vertebral compression fracture. METHODS: A retrospective review of 34 kyphoplasties for single-level osteoporotic vertebral compression fractures was performed. Pain relief was assessed by using the visual analogue scale (VAS) at preoperatively and postoperatively at 6 weeks, 3 months, and 6 months. Associated factors, including age, sex, pain duration, bone mineral density, and cement leakage, were evaluated using the patients' medical records. Statistical analyses were conducted using the paired t-test to assess pain relief and using the independent t-test and Pearson's correlation coefficient to evaluate the relationship between those factors and pain relief. RESULTS: Preoperatively, the mean VAS score was 7.06. Postoperatively, it declined to 3.66 (p=0.001), 2.81 (p=0.001) and 2.24 (p=0.001) at 6 weeks, 3 months and 6 months, respectively. Also, statistically significant pain relief was observed during the periods from 6 weeks to 3 months (p=0.001) and from 3 months to 6 months (p=0.001). However, reduction of the VAS score showed no significant correlation with age, sex, pain duration, bone mineral density, or cement leakage (p>0.05). CONCLUSION: Our study suggests that a kyphoplasty may be effective in osteoporotic vertebral compression fracture patients with acute pain and that after the kyphoplasty, pain is reduced remarkably for 6 weeks and then continuously for 6 months.