OBJECTIVE: To compare the effectiveness and acceptability of silver ring splints (SRS) and commercial prefabricated thermoplastic splints (PTS) in treating swan neck deformities in patients with rheumatoid arthritis (RA). METHODS: Consecutive patients with RA and a mobile swan neck deformity were included in a randomized, crossover trial. In 2 different sequences, patients used both splints for 4 weeks, with a washout period of 2 weeks. Afterward, patients used the preferred splint for another 12 weeks. The primary outcome measure was dexterity measured with the Sequential Occupational Dexterity Assessment (SODA). Secondary outcome measures included other measures of hand function, satisfaction with the splints, and splint preference. RESULTS: Fifty patients were included, and 47 (94%) of those completed the study. Eighteen patients (36%) had 1 swan neck deformity, whereas the other patients had 2 or more. The improvement of the total SODA score with the SRS (11.2; 95% confidence interval [95% CI] 8.1, 14.3) and PTS (10.8; 95% CI 7.5, 14.1) was similar (difference -0.5; 95% CI -2.2, 1.2). In addition, there were no significant differences in change scores regarding the other clinical outcome measures, or satisfaction. Twenty-four patients preferred the SRS, 21 preferred the PTS, and 2 patients chose neither. A comparison in the 12-week followup period yielded similar clinical outcomes, with the exception of a significantly higher score in 3 items of satisfaction in the SRS group. CONCLUSION: For patients with RA and a mobile swan neck deformity, SRS and PTS are equally effective and acceptable.