Fuchs' heterochromic cyclitis (FHC) is an important diagnosis to make. Not only for the patient, because incorrect diagnosis may lead to unnecessary therapy and the failure to detect secondary glaucoma, but also for the comparison of studies on the etiology of FHC, which is still unknown. No clinical criteria for establishing the diagnosis of FHC have been internationally accepted yet. By means of clinical analyses of FHC patients in different parts of the world, predominant clinical features may be distinguished and combined to form (internationally accepted) diagnostic criteria. We report a clinical analysis of 51 FHC patients in the Netherlands. Acute symptoms (severe redness, pain or photophobia) were never (100%) encountered. Characteristic keratic precipitates (88%) and/or minimal aqueous cells and flare (60%) and/or vitreous opacities (84%) were major signs, indicating a chronic inflammatory activity, in which no synechiae (100%) were present. Heterochromia (82%) was not a constant sign, but iris stromal atrophy, which causes the heterochromia, was always present (100%). Cataract was present in 82% as a result of the chronic iridocyclitis. Secondary glaucoma was present in 22%. Based on the predominant clinical findings obtained from this analysis of FHC patients, and on data in the literature, we propose clinical diagnostic criteria for FHC. Future studies, also including other uveitis groups, are necessary to confirm these diagnostic criteria.