Objective To compare the effectiveness between unilateral and bilateral percutaneous kyphoplasty (PKP) in the treatment of Kümmell disease. Methods The clinical data of 45 patients with Kümmell disease that met the criteria between January 2014 and February 2016 were analyzed retrospectively. Among them, 26 cases were treated by unilateral PKP (unilateral group), 19 cases were treated by bilateral PKP (bilateral group). There was no significant difference in gender, age, disease duration, injured vertebral segment, bone mineral density (T value), and the preoperative visual analogue scale (VAS) score, Oswestry disability index (ODI), anterior vertebral height, and kyphosis Cobb angle between 2 groups (P>0.05). The operation time, intraoperative fluoroscopy times, amount of injected bone cement, and hospitalization time were recorded, and the situation of bone cement leakage was observed. The VAS score, ODI, anterior vertebral height, and kyphosis Cobb angle were evaluated before operation, at 1 day after operation, and at last follow-up. Results Bone cement leakage during the operation were found in 4 cases (15.38%) of unilateral group and 3 cases (15.79%) of bilateral group without obvious neurological symptoms; there was no significant difference in the incidence of bone cement leakage between 2 groups (χ2=0.000, P=1.000). The operation time, intraoperative fluoroscopy times, and amount of injected bone cement in the unilateral group were significantly lower than those in the bilateral group (P<0.05); but there was no significant difference in the hospitalization time between 2 groups (P>0.05). The X-ray film examination showed that there was no pulmonary embolism in all patients at 1 day after operation. All the patients were followed up 12-24 months, with an average of 16.4 months. There was no complication such as vertebral re-fracture or cement block displacement in the injured vertebra. The VAS score, ODI, anterior vertebral height, and kyphosis Cobb angle at 1 day after operation and at last follow-up were significantly improved when compared with preoperative values in 2 groups (P<0.05); the VAS score and ODI in 2 groups were further reduced at last follow-up when compared with the value at 1 day after operation (P<0.05), but the anterior vertebral height and kyphosis Cobb angle in 2 groups at last follow-up did not change significantly (P>0.05). There was no significant difference in above indexes at 1 day after operation and at last follow-up between 2 groups (P>0.05). Conclusion Both unilateral and bilateral PKP can achieve good effectiveness in treatment of Kümmell disease. But the unilateral puncture technique possesses advantages such as shorter operation time, less radiation dose, and less amount of injected bone cement.