Melasma is a specific type of facial hyperpigmentation seen in women taking oral contraceptives, in non-pregnant women who have not used oral contraceptives, and in some pregnant women during the progression of gestation, but rarely in men. Circulating LH, FSH, PRL, and E2-17 beta on day 5, 7, 9, and 11 of the menstrual cycle and progesterone (P) on day 17, 19, and 21 were measured in thirty-six ovulating women with melasma (study group) age 25-35 years and twelve healthy controls (control group). Twenty-seven subjects in the study group had normal pregnancies; 9 others were married or single and had no history of contraceptive pill use. Higher levels of FSH on day 7 (p < 0.05); E2-17 beta on 5, 7, 9 (p < 0.05) and LH on day 9 (p < 0.002) were observed in the study group than in the control group. There were no significant differences between the LH/FSH ratio in the two groups. Serum PRL was lower on day 9 in the study group (p < 0.05) than in the control group. Serum P was similar in the patients and the controls. These findings indicate a possible role of high E2-17 beta in the maintenance of melasma.