This study examined changes in mobility methods of children with cerebral palsy (CP) over time and across environmental settings. Sixty-two children with CP, ages 6-14 years and classified as levels II-IV on the Gross Motor Function Classification System, were randomly selected from a larger data base and followed for three to four years. On each of several assessments, parents completed a questionnaire on their child's usual mobility methods in the home, school, and outdoors/community settings. During the first assessment interval, mobility methods increased to methods requiring more gross motor control. During the second assessment interval, mobility methods were unchanged or decreased to methods requiring less gross motor control. Changes within the child and within the environment are hypothesized to occur and to impact changes in mobility methods. Screening at regular intervals is recommended to monitor changes in mobility. Interventions to enhance mobility may be indicated during periods of change in the child or exposure to new environments. (Contains 2 figures and 5 tables.)