Abstract
Isolated unilateral pleural effusion is uncommon presentation of ovarian hyper stimulation syndrome. The pathogenesis of this syndrome involved an increased permeability of the ovarian capillaries and of the mesothelial vessels triggered by the release of vasoactive substances by the ovaries under human chorionic gonadotropin stimulation. Early recognition of this unusual presentation of ovarian hyperstimulation syndrome should allow for physicians to ensure a better and minimally invasive management of these potentially pregnant patients.