The use of laparoscopic surgery in gynecologic oncology might be complicated by unsuspected side-effects for the patient. Experimental data suggest that the risk of tumor dissemination in the non traumatized peritoneum may be higher after pneumoperitoneum than after laparotomy, and they also show the importance of the surgeon's experience and technique.We present two cases of uterine endometrial stromal tumors which were laparoscopically excised. In both cases, intraperitoneal tumor seedings were identified shortly after the initial operation. The first patient had a low-grade endometrial stromal sarcoma and succumbed from the disease two years after the initial operation, while the second patient who was diagnosed with endometrial stromal tumor remains disease free two years later.The laparoscopic excision of an endometrial stromal tumor might result in tumor dissemination into the abdominal cavity. A careful second-look examination of the abdomen or a radical surgical approach is proposed.