Abnormalities in choroidal perfusion have been hypothesized to be causative factors in central serous chorioretinopathy. This prospective study was performed to evaluate changes in the choroidal circulation in cases of central serous chorioretinopathy. In 32 consecutive patients with acute or chronic recurrent central serous chorioretinopathy, complete clinical ophthalmologic examinations, fluorescein angiography, and indocyanine green angiography with a scanning laser ophthalmoscope and a digital imaging system were performed. All patients with acute and chronic recurrent central serous chorioretinopathy demonstrated a localized delay in arterial filling followed by choroidal hyperperfusion in the area of the damaged retinal pigment epithelium, frequently associated with dilated capillaries and dilated draining venules in one or more choroidal lobules. These changes corresponded to areas with pigment epithelial detachment or focal leakage from the retinal pigment epithelium found in fluorescein angiography. Furthermore, in some patients, localized choroidal ischemia could be observed in additional areas throughout the central fundus in both diseased eyes and normal fellow eyes. Delayed arterial filling followed by capillary and venous hyperemia, angiographically appearing as capillary and venous congestion, can be observed frequently in eyes with central serous chorioretinopathy. The results suggested that capillary or venous congestion after ischemia in one or more choroidal lobules might be the reason for the choroidal hyperpermeability associated with central serous chorioretinopathy.