Introduction: Impairment is the direct exteriorization of disease consequences, and disability is restriction or absence of any activity due to impairment. Objectives: To identify impairments and disabilities of psychomotor development and characteristics of patients treated at the Department of Investigation, Teaching and Integral Rehabilitation of Development Disabilities. Design: Observational, descriptive, cross-sectional study. Setting: Instituto Nacional de Rehabilitacion Dra. Adriana Rebaza Flores, Callao, Peru. Participants: Patients treated from 0 to 7 years with definite diagnosis and no evident mental retardation. Interventions: From 5 795 patients attended in the period 2006-2008 we reviewed a sample of 400 medical records, and studied impairments and disabilities and their characteristics. Main outcome measures: Impairments and disabilities of psychomotor development. Result...