The classification, size and activity of choroidal neovascularization (CNV) by optical coherence tomography (OCT) were compared with those obtained by fluorescein angiography (FA) and Indocyanine green angiography (ICG). This study included 32 patients (32 eyes) diagnosed as having CNV. The etiology of CNV was found to be age-related macular degeneration (AMD) or non-AMD. Patients were studied retrospectively by FA, ICG, and OCT. Of the 13 eyes with AMD, the boundary of the lesion could not be defined using FA in 7 patients. Among the 7 poorly defined CNV cases by FA, the identification of the boundary was possible in one case by OCT. The mean diameter of the classic well-defined lesions was 3500 +/- 421 microm by FA, 2624 +/- 1044 microm by ICG, and 1927 +/- 1272 microm by OCT. The size of the CNV by OCT was always smaller than by FA or ICG. Of the 19 eyes with Non-AMD, the boundary of the lesion could not be defined by FA in 5 patients. Among the 5 poorly defined cases by FA, the identification of the boundary was possible in 3 cases by OCT. The mean diameter of the well-defined CNV lesions was 2153 +/- 759 microm by FA, 1929 +/- 673 microm by ICG, and 1322 +/- 566 microm by OCT. Retinal thickness, which represents retinal edema, was found to be proportional to lesion size, although the relationship was not statistically significant. Regardless of CNV type, FA, ICG and OCT used in combination increase the specificity of diagnosis if their findings are compared.