OBJECTIVE: To describe a case of coincidental finding of splenosis during gynecological laparoscopic surgery. DESIGN: Case report. SETTING: Department of gynecology and obstetrics, Hospital of Frýdek-Místek. CASE REPORT: We describe the case of coincidental perioperative finding of pelvic tumorous mass that was later histologicaly verified as accsessory spleen or splenosis. CONCLUSION: Ectopic spleen is mostly random finding with no symptoms observed. Rarely it can cause pelvic pain or mimick adnexal malignity or endometriosis. It is neccesery to keep this rare diagnosis in mind, mainly at patients with splenic trauma or splenectomy in their medical history to preserve immunological function of this splenic tissue.