Sildenafil is used to treat pulmonary hypertension (PAH) in infants with congenital diaphragmatic hernia (CDH). However, data to guide sildenafil dosing and weaning are limited. This is concerning in light of a recent report describing increased risk associated with high-dose sildenafil regimens in non-CDH PAH. A retrospective cohort study of sildenafil usage, dosing, and weaning in infants with CDH was conducted at the authors' institution. The findings show that 17 % (19/122) of infants were discharged receiving sildenafil at a median dose of 8 mg/kg/day (range 2.91-5.78 mg/kg/day). The weaning rate was 0.1 mg/kg/week (range 0.01-0.5 mg/kg/week). The infants ceased therapy after a median of 343 days. At the age of 1 year, 29 % were receiving sildenafil at a dose higher than 1.5 mg/kg/day. One infant died of severe PAH. Sildenafil therapy at discharge is common in severe CDH. Variation in dosing and weaning rates highlights the need for standardized assessment and treatment of PAH after discharge to optimize the benefits and minimize the adverse effects of sildenafil.