Recent technological advances in optical and surgical devices have resulted in laparoscopic surgery for gastric and colorectal cancer, gaining wider acceptance and becoming more common. Simultaneous laparoscopic surgery for gastric and colorectal cancer has many potential advantages, including a small incision, good cosmetic result, less postoperative pain, and less mobility. However, some problems have to be resolved. To clarify the anastomotic problem of combined abdominal minilaparotomy, we present here 2 typical cases of simultaneous laparoscopic surgery for gastric and colorectal cancer. Case 1: The anastomoses after laparoscopic right hemicolectomy and distal gastrectomy were easily performed by combined upper abdominal minilaparotomy. Case 2: The anastomosis after laparoscopic right hemicolectomy was easily performed by upper abdominal minilaparotomy. However, the ensuing esophago-jejuno anastomosis after laparoscopic total gastrectomy resulted in failure during combined upper abdominal minilaparotomy because the anastomotic angle was incomplete. In conclusion, the choice of abdominal mini-incision site is crucial during simultaneous laparoscopic surgery for gastric and colorectal cancer. Surgeons should not hesitate to perform an additional mini-incision or change other anastomotic procedures if the operation is difficult, requires a long time to complete, and is likely to cause intraoperative complications.