PURPOSE: To describe a cohort of children with late-recognized primary congenital glaucoma (LRPCG), including age of presentation, age-related diagnostic signs, clinical abnormalities, and results of glaucoma surgery. METHODS: The medical records of 31 patients (49 eyes) with PCG recognized after 1 year of age were reviewed retrospectively. Patients were confirmed to have PCG based on their increased intraocular pressure (IOP), anterior segment abnormalities including findings on gonioscopy, and the absence of other causes of childhood glaucoma. The outcome of glaucoma surgery was reviewed and success measured by assessment of the relative control of IOP, occurrence of significant complications, and need for additional glaucoma surgery. RESULTS: Average age at diagnosis of glaucoma was 4.7 years (36% diagnosed at > 4 years of age). The most common initial diagnostic signs were corneal enlargement (46%, average age of 2.0 years), photophobia (20%, average age of 3.3 years), and suspected poor visual acuity (32%, average age of 9.9 years). Corneal cloudiness was not an initial sign for any patient. Haab's striae were present in 60% of the affected 49 eyes. Gonioscopy findings were abnormal in 82%, but the ciliary body band was seen in 81% and the scleral spur was visible in 47%. Sixty-one goniotomy procedures were performed for 39 eyes with overall success in 95% (37 eyes) and complete success in 65% (27 eyes). The final visual acuity was 20/200 or worse in 31% (15 eyes) and 20/40 or better in 60% (29 eyes). CONCLUSIONS: An awareness of and familiarity with the subtle diagnostic signs of LRPCG can enable its differentiation from primary juvenile glaucoma and contribute to earlier recognition and treatment. Glaucoma surgery is often required for LRPCG and goniosurgery is the recommended initial procedure.