To explore the characteristics of pediatric primary retroperitoneal teratoma and the influencing factors of perioperative complications. The clinical data, imaging data, pathology results, perioperative complications, etc of patients with primary retroperitoneal teratoma admitted and treated at Shanxi Children's Hospital from March 2013 to September 2023 were retrospectively analyzed. The patients were divided into no complication group and complication group according to whether there were perioperative complications. The differences between the two groups were compared, and the influencing factors of complications were analyzed by multivariate logistic regression model. A total of 33 patients were included in this study, including 7 males and 26 females, with an age of [M (Q1, Q3), 9.0 (4.0, 24.0)] months. Nineteen cases had tumors located in the left upper abdomen and 14 cases in the right upper abdomen, among which 17 cases grew across the midline, with the maximum tumor diameter of (12.9±4.5) cm. All patients had anatomical displacement of retroperitoneal vessels and organs: the number of anatomical displaced arteries was 3 (3, 4), the number of anatomical displaced veins was 4 (3, 5), the number of anatomical displaced organs was 5 (4, 6). Pathologic examination revealed 28 mature teratomas (Grade 0 and Grade 1) and 5 immature teratomas (Grade 2 and Grade 3). There were 18 cases in no complication group and 15 cases in the complication group. The incidence of perioperative complications was 45.5% (15/33). The number of tumors crossing the midline (6/18 vs 11/15, P=0.037), the number of tumors adhering closely to the surrounding tissues (7/18 vs 12/15, P=0.033), the number of anatomical displaced veins [4 (3, 4) vs 5 (4, 5), P=0.001], and the number of anatomical displaced organs [4 (3, 5) vs 6 (5, 6), P=0.001] were significantly different between the two groups. Multivariate logistic regression model analysis showed that the number of anatomical displaced organs (OR=8.781, 95%CI: 2.155-35.784, P=0.002) was the influencing factor for perioperative complications of pediatric primary retroperitoneal teratoma.