Background: Laparoscopic adrenalectomies are being performed increasingly, either with transperitoneal or retroperitoneal approaches. Studies comparing the 2 approaches have not shown the superiority of either technique, but these studies are limited by small sample sizes and single-institution designs. To overcome these limitations, we performed a meta-analysis of studies comparing lateral transperitoneal adrenalectomy and retroperitoneal adrenalectomy. Methods: A systematic review of studies comparing lateral transperitoneal adrenalectomy and retroperitoneal adrenalectomy was conducted. Study endpoints included perioperative outcomes and measures of postoperative recovery. Meta-analysis was performed using a random effects model, pooling variables evaluated by more than 3 studies. Results: Twenty-one studies comparing a total of 1,205 lateral transperitoneal adrenalectomies and 688 retroperitoneal adrenalectomies were suitable for meta-analysis. Patients in the 2 groups were similar in term of age, sex, body mass index, lesion size and location, and rates of malignancy. There were no statistically significant differences between lateral transperitoneal adrenalectomy and retroperitoneal adrenalectomy in terms of operative time, blood loss, hospital stay, time to oral intake, overall and major morbidity, and mortality. Conclusion: Both lateral transperitoneal adrenalectomy and retroperitoneal adrenalectomy are associated with very low rates of perioperative complications. According to our meta-analysis, clinical outcomes after either technique are similar. For most adrenal lesions requiring operation, minimally invasive adrenalectomy can be performed safely and effectively with either transperitoneal or the retroperitoneal approach. Additional studies may be needed to analyze if any difference in long-term results exist.