We performed an evaluation of ultrasound-guided transvaginal aspiration of ovarian cysts as a viable alternative to surgery in 104 reproductive and 17 postmenopausal women. One-hundred and twenty-one patients with a simple >4 cm diameter ovarian cyst, with a benign appearance on ultrasound as well as on clinical and blood examination, underwent transvaginal fine needle aspiration of the cyst under ultrasonographic control. One-hundred and four patients were of reproductive age and 12 were postmenopausal. Sixty women who were of reproductive age and in which OCP treatment was not contraindicated followed a six-month therapy with oral contraceptives after the intervention. In the group of patients of reproductive age under OCP treatment the cyst persisted in nine of the 60 women (recurrence rate 15%). In the other group of patients of reproductive age,under no OCP treatment, the recurrence rate was 47% (21 of the 44 women). In the group of postmenopausal patients, the cyst persisted in ten out of 17 cases (recurrence rate 58,9%). Transvaginal aspiration of ovarian cysts is a reliable alternative to surgery with many advantages such as excellent tolerance, low risk and cost of complications and recurrence. The OCP treatment after aspiration seems to increase the success rate of expectant management.