An Adh duplication is described in the medfly Ceratitis capitata. Evidence is presented for two separate Adh1 and Adh2 structural loci mapping at a distance of 0.49 recombination unit from each other. By deletion mapping the Adh region has been cytologically located near the free end of the left arm of the second chromosome within an area between 2C;3A segments of the polytene chromosome. The genetic analysis of the region around Adh has identified seven neighboring genes (Acon1, Mpi, Est6, Aox, Xdh, Mdh2, Lsp1) which identify the linkage group D. The orientation of loci with regard to the centromere sets the origin of the map of the left arm of the second chromosome close to the two Adh loci.