Background: Ovarian cysts are frequently common in practice at reproductive age. The management of the cystic adnexal mass in women of reproductive age remains a common gynaecological problem. It is widely accepted that many adnexal cysts represent a persistence of an ovarian follicle or cystic corpus luteum. Aim of the work: The aim of the study is to determine the usefulness of use of progestins over expectant management in treatment of functional ovarian cyst. Methods: 90 women with ovarian cysts were recruited and divided into either control group or progesterone group. The patients were monitored after 6 to 8 weeks. Results: The percentage of 50% or more reduction in cyst width in progesterone group was 35.6% while the control group was 17.8%. The percentage of 50% or more reduction in cyst length in progesterone group was 24.4% while the control group was 15.6%. The percentage of 50% or more reduction in cyst depth in progesterone group was 24.4% while the control group was 17.8%. After testing, there no significant difference detected between both treatment modalities regarding cyst length (p = 0.097), cyst width (p = 0.385), cyst depth (p = 0.204). Cysts resolved completely in 26/45 (57.9%) and 17/45 (37.8%) in groups progesterone and control respectively, However, there was no significant difference regarding content (p = 0.059) and cyst disappearance (p = 0.058). Conclusion: Progestin therapy in functional cysts could be effectively used as expectant management at least among women who are having spontaneous ovulation.