We compared external trabeculotomy and goniotomy in similar groups of patients with developmental glaucoma. External trabeculotomy was statistically more successful as a first operation (19 of 23 eyes, 83%) than goniotomy (eight of 24 eyes, 33%) (P = .003). With multiple operations both procedures controlled intraocular pressure in most patients but more operations were required after goniotomy (31 procedures in 12 eyes) than after external trabeculotomy (13 procedures in eight eyes) than after occurred within one year of surgery (six of eight failures with external trabeculotomy and 20 of 23 failures with goniotomy).