We studied the clinical characteristics and the natural course of occult choroidal new vessels (CNV) in 78 eyes with age-related macular degeneration (AMD). Cases were included in 2 groups characterized respectively by ill-defined subretinal ooze (group 1) and serous detachment of the retinal pigment epithelium (RPE) with adjacent areas of mottled pigmentation (group 2). Both these forms of occult CNV showed to have a slower evolution compared to the classic CNV occurring in AMD, but they also led to disciform scar and severe visual loss. Occult CNV of group 2, contrary to those of group 1, were often multifocal and extrafoveal. They had a greater tendency to hemorrhages and a faster and less gradual progression to fibrovascular scarring and visual loss. Fluorescein angiography showed choroidal filling delay in the macular region of 47% of eyes of group 1. A perfusion defect of the macular choroid could be the basis of the low perfusion pressure and the consequent low activity of CNV with the angiographic pattern of ill-defined ooze.