PURPOSE/METHODS: To establish the association of a macular pattern dystrophy with maternally inherited diabetes and deafness, a new subtype of diabetes mellitus caused by a mutation of mitochondrial DNA (mtDNA). Two probands of two different families with maternally inherited diabetes and deafness were examined. RESULTS/CONCLUSION: Both probands exhibited a macular pattern dystrophy, maternally inherited in one patient. The association of a macular pattern dystrophy with diabetes should lead to screening for a mutation of mtDNA.