Introduction. Laparoscopic and robot-assisted laparoscopic surgery are widely performed in urology field, so Hem-o-Lok clips are thus extensively used in the laparoscopic procedures. We describe the first case of Hem-o-Lok clip which migrated into the neobladder with calculus formation 26 months after laparoscopic orthotopic neobladder cystectomy, which causes symptoms of gross hematuria and frequent urination. Case Presentation. A 57-year-old man with T2a muscle invasive bladder cancer underwent laparoscopic orthotopic sigmoid neobladder reconstruction after cystectomy which was complicated by intestinal anastomosis leak and peritoneal abscess requiring transverse colostomy and drainage 15 days postoperatively. Twenty-six months after cystectomy, he complained of gross hematuria and frequent urination. Computerized tomography and plain pelvic X-ray revealed a stone measuring approximately 2.8 cm in diameter in the neobladder. During cystoscopy, a closed whitish Hem-o-Lok clip was seen in the center of the calculi. No anastomotic leak or neoplasm was found during cystoscopy. Conclusion. Hem-o-Lok clip migration into the bladder after laparoscopic orthotopic neobladder cystectomy is a rare complication; the first reported case in the literature. To prevent Hem-o-Lok clip migration, it is recommended to avoid extensive use of Hem-o-Lok clip close to anastomosis site, and any loose Hem-o-Lok clip should be retrieved before closure.