This is a retrospective study between 2013 to 2016 of 452 eyes of patients </=12 years with primary congenital glaucoma (PCG), who underwent either goniotomy (GT) (median age: six months, 120 eyes) or trabeculotomy (TBT) (median age: 5.2 months, 332 eyes). Failure was defined as intraocular pressure (IOP) >/=18mmHg while on medications or further glaucoma surgery. In the GT group, the failure rate was 56% and was influenced by the preoperative cup-disc ratio. The median IOP reduction was 19.4% and was positively correlated to a high initial IOP (p</=0.001). In the TBT group, the failure rate was 30% and was influenced by positive consanguinity, higher preoperative IOP, female gender and younger age at surgery. The median IOP reduction was 36.8% and mostly influenced by preoperative IOP, corneal opacity, gender and consanguinity. The authors concluded that TBT appears to be superior to GT in PCG but potential bias towards TBT has to be considered in cases which had previous angle surgery or eyes with opaque corneas.