We used a dog model to test the safety and effectiveness of sutureless gastrointestinal anastomoses (n = 23) (end-to-end, end-to-side, or side-to-side) with the nickel-titanium double ring with temperature-dependent shape memory. Results were compared to conventional hand-sutured anastomoses (n = 5). Examination performed after 2 weeks' follow-up showed no leaks and no difference in return of bowel function between the experimental groups and the control group. Microscopic studies showed a complete epithelial lining and perfectly functioning anastomoses. We conclude that the nickel-titanium double-ring device may have an important place in the armamentarium of the gastrointestinal surgeon.