Aim: To compare function and gait in a group of children older than most children who received selective dorsal rhizotomy (SDR) with age- and function-matched peers who received either orthopedic surgery or no surgical intervention. Method: A retrospective study examined ambulatory children with diplegic cerebral palsy, aged between 10 years and 20 years and categorized in Gross Motor Function Classification System (GMFCS) levels I or II. Three groups were considered: (1) children who had selective dorsal rhizotomy (n = 8; two females, six males; mean age 15y 4mo at SDR, 16y 8mo at follow-up); (2) children who had orthopedic surgery (n = 9; three females, six males; mean age 14y 6mo at SDR, 15y 1mo at follow-up), and (3) children who had no surgical intervention (n = 9; two females, seven males; mean age 15y 6mo at follow-up). Longitudinal measures of gait analysis (velocity, gait deviation index, and gait variable scores) and gross motor function (GMFCS level, Gross Motor Function Measure scores, and centiles) were examined. Results: No significant differences were found between changes in gait comparing rhizotomy with orthopedic surgery; however, the group who received orthopedic surgery demonstrated improved gait compared with the group without surgical intervention. Longitudinal comparisons of gross motor function demonstrated a decrease in the group who received SDR. Between-group analysis of outcomes also demonstrated worse outcomes of the SDR group compared with the orthopedic surgery group and with the no surgical intervention group. Interpretation: Rhizotomy in older children was associated with functional declines compared with similar children who had no surgery and with those who underwent orthopedic surgery. This suggests that age greater than 10 years might be a contraindication for SDR if the goal is to improve motor skills.