Objective: To evaluate the activity and participation levels of adults with spastic diplegia 17-26 years after selective dorsal rhizotomy; to investigate relationships between subjects'functioning and age, socio-economic-status, level of satisfaction and their perceptions of the post-operative outcomes. Design: Observational follow-up study.Patients: Thirty-one subjects with spastic diplegia, age range 21-44 years, who underwent selective dorsal rhizotomy between 1981 and 1991. Methods: A semi-structured interview was used to gather data on patients' characteristics and long-term experiences after the operation. The Functional Mobility Scale and Life-Habit questionnaire were completed.Results: Based on the Functional Mobility Scale 84% of subjects were reported as independent for a distance of 5 m, and 61% for 50 and 500 m. Eighty percent were independent in accomplishing all life habits, with most problems found for Mobility and Recreation. This was in agreement with the subjects' perception, with strong correlations between Life-Habit questionnaire accomplishment and satisfaction levels. No significant associations were found between functioning and age at selective dorsal rhizotomy, current age and socioeconomic status. Conclusion: More than 15 years after selective dorsal rhizotomy, adults with spastic diplegia showed high levels of functioning, and similar levels of satisfaction with life habits. The majority had positive feelings about the neurosurgical procedure, although there is a need for better follow-up after subjects leave school