ObjectiveThe first-line treatment of lymphatic malformations (LMs) is pharmacological or interventional; however, surgery is still necessary in selected cases. Our aim was to identify factors associated with the occurrence of permanent postoperative complications. MethodsThis was a case series study of children operated on for LMs between 2001 and 2021 and followed-up in our institution. Patients who presented sequelae derived from surgical treatment (cases) and those who did not (controls) were compared. ResultsWe included 112 children who underwent surgery for LMs in different centers. Forty-nine cases and 63 controls were included (58% male), with a mean age of 34 months. Patients younger than 1 year presented more complications than older children, 59% (n = 29/49) vs 41% (n = 24/49), respectively (P = .02). LMs were in the cervicofacial region in seven patients in the control group compared with 30 of the cases (P ≤ .001), with microcystic malformations the most associated with sequelae (n = 11/15; P = .019). Concerning permanent complications, 88% were neurological (n = 43/49), mainly peripheral facial palsy (n = 17). There was greater postoperative residual disease in controls compared with cases (65% vs 14%, respectively; P ≤ .0001). However, following a second procedure in the control group, there was no significant difference in long-term cure rates (P = .38). ConclusionsThe risk of sequelae following surgery for LM increases significantly in patients younger than 12 months in cervicofacial and microcystic malformations. Because non-radical resections are associated with fewer complications and an optimal long-term cure rate, we consider that aggressive surgical approaches should be avoided if the absence of sequelae is not guaranteed.