Objective: To assess the effectiveness of group wheelchair skills training to elicit improvements in wheelchair skills. Design: Randomized double-blinded controlled trial. Setting: Four Spinal Cord Injury Model Systems Centers. Participants: Manual wheelchair users with spinal cord injury (N=114). Intervention: Six 90-minute group Wheelchair Skills Training Program (WSTP) classes or two 1-hour active control sessions with 6 to 10 people per group. Main Outcome Measures: Baseline (t1) and 1-month follow-up (t2) Wheelchair Skills Test Questionnaire (WST-Q) (Version 4.2) for capacity and performance and Goal Attainment Scale (GAS) score. Results: Follow-up was completed by 79 participants (WSTP: n=36, active control: n=43). No differences were found between missing and complete cases. Many users were highly skilled at baseline with a WST-Q capacity interquartile range of 77% to 97%. There were no differences between groups at baseline in WST-Q measures or demographics. Compared with the active control group, the WSTP group improved in WST-Q capacity advanced score (P=.02) but not in WST-Q capacity or WST-Q performance total scores (P=.068 and P=.873, respectively). The average GAS score (0% at t1) for the WSTP group at t2 was 65.6%±34.8%. Higher GAS scores and WST-Q capacity scores were found for those who attended more classes and had lower baseline skills. Conclusions: Group training can improve advanced wheelchair skills capacity and facilitate achievement of individually set goals. Lower skill levels at baseline and increased attendance were correlated with greater improvement.