We developed a diagnostic test based on the reverse dot-blot principle, in which five mitochondrial point mutations responsible for Leber hereditary optic neuropathy (LHON) were screened simultaneously. A series of wild-type and mutant oligonucleotides representing each mutation were covalently bound to a single nylon membrane strip. The target sites were amplified in a multiplex PCR and the products were hybridized to the membrane. Detection is based on chemiluminescence. To test the developed assay, 47 patients suspected of having LHON were screened. In 11 cases (23%) the diagnosis of LHON could be confirmed (3460, 1; 9804, 1; 11778, 5; 14484, 3; 15257, 1). The results suggest that the clinical identification of the mitochondrial defect is not trivial and the availability of a rapid screening method simplifies the molecular analysis of these cases.