Aim: To determine the long-term course of difficulty in participation of individuals with cerebral palsy (CP) without intellectual disability between 16 years and 34 years of age. Method: One hundred and fifty-one individuals with CP aged 16 to 20 years were included (63% male, 37% female; Gross Motor Function Classification System [GMFCS] levels I–IV; without intellectual disability). The Assessment of Life Habits questionnaire 3.0 general short form was used up to three times biennially and at 13-year follow-up (13-year follow-up: n=98). Scores (range 0–10) reflect difficulty and assistance in participation in housing, education and employment, interpersonal relationships, recreation, community life, and responsibilities. Multilevel models were used to determine the course of difficulty in participation by GMFCS level. Results: Despite high average participation levels, 41% to 95% of adolescents and young adults with CP experienced difficulty. Difficulty in participation in housing and interpersonal relationships increased from age 16 years onwards and in most other life areas in the mid- and late 20s. In adolescents in GMFCS levels III and IV, participation in recreation and community life improved up to age 23 years. Interpretation: Individuals with CP experience increasing difficulties in participation in their mid- and late 20s. Clinicians should systematically check for participation difficulties in young adults with CP and offer timely personalized treatment. What this paper adds: Many individuals with cerebral palsy (CP) aged 16 to 34 years experience difficulty in participation. Difficulty in participation increases in the mid- and late 20s for individuals with CP. Participation in recreation/community life improves before age 23 years for those in Gross Motor Function Classification System levels III and IV.