[Objective] To compare the clinical results of posterior hemivertebrotomy for treatment of spinal deformities due to single hemivertebra in different ages. [Methods] A retrospective study was performed on 80 children who underwent posterior hemivertebrotomy for spinal deformities due to single hemivertebra in our department from January 2013 to December 2020. Based on the age at operation, 43 children who aged 3 to 6 years were fall into the young group, while 37 children who aged more than 6 to 10 years were enrolled into the old group. The perioperative, follow- up and radiographic documents were compared between the two groups. [Results] All children in both groups had the surgical procedures completed smoothly without complications, such as nerve and vascular injury. The young group con- sumed significantly shorter operative time, associated with significantly less intraoperative blood loss and segments fixed than the old group (P＜0.05) . Patients in both groups were followed up for 10~12 months, with an average of (11.05±0.84) months. The sitting height and stand- ing height significantly increased in both groups over time (P＜0.05) , while there were no significant differences in the time to resume walk- ing and full weight-bearing activity, the variation rate of sitting height and the incidence of complications between the 2 groups (P＞0.05) . Radiographically, kyphotic Cobb angle, scoliotic Cobb angle, and C₇PL-CSVL were significantly reduced in both groups immediately after surgery and at the last follow-up compared with those preoperatively (P＜0.05) . At corresponding time points, they young group had signifi- cantly less kyphotic Cobb angle, scoliotic Cobb angle and C7PL-CSVL than the old group (P＜0.05) . There was no statistical significance in the correction rate of kyphotic and scoliotic Cobb angles and the correction rate of C₇PL-CSVL between the two groups immediately after surgery and at the last follow-up (P＞0.05) . Pearson correlation analysis found that age was positively correlated with operating time and blood loss (P＜0.001) , but not correlated with sitting height change rate, kyphotic Cobb angle, scoliotic Cobb angle, and C₇PL correction rate (P＞0.05) . [Conclusion] Early posterior hemivertebrotomy for spinal deformities due to single hemivertebra might be conducive to shorten the operation time, reduce intraoperative blood loss and fixed segments.