Studies have suggested disparate variables affecting long-term outcomes in patients with infantile spasms. Using a retrospective chart review, the authors identified 109 patients who had follow-up data for at least 1 year since the onset of spasms. Patient and treatment variables were recorded, in addition to neurodevelopmental and seizure outcomes. Etiology was strongly associated with motor and cognitive status but not with long-term seizure control. Lag time to initiation of treatment was not predictive of any outcome, nor for need to use a second agent to resolve spasms, even when controlling for etiology. However, patients who responded to the first medication achieved superior seizure and cognitive outcomes. The delayed impact of individual medications could not be analyzed because many patients received multiple agents. While etiology and response to first medication predict better outcomes, the majority of patients with infantile spasms continue to have epilepsy with long-term motor and cognitive disabilities.