We report a case in which a patient received IVF treatment due to massive pelvic endometriosis. The tubal patency and sperm parameters were normal. After e-SET (elective single embryo transfer) ultrasonography showed a triplet pregnancy with thick dividing membranes and lambda sign between all sacs. Two monozygotic and one dizygotic girl were delivered by Caesarean section at 28 weeks gestation. The couple had intercourse 2 days prior to the oocyte pick up (OPU) and the triplet pregnancy was attributed to a combination of assisted and spontaneous conception.