The DNA sequence of a 3886-bp genomic region containing the alcohol dehydrogenase (Adh) gene fromDrosophila affinidisjuncta, and the RNA sequences of theD. affinidisjuncta Adh transcripts, are presented. These data support the conclusion that twoAdh promoters generate distinct, developmentally regulatedAdh transcripts. Correlations between these sequences and the transcription map are discussed. Comparisons between these and equivalent data fromD. melanogaster are also presented. We note the following observations: (1) Except at the extreme 3 end, the two genes are identically organized. (2)Drosophila Adh protein accumulates amino acid replacements at the rate of approximately 0.5 per million years. (3) Among the non-protein-coding DNA sequences, putative homologies occur in the two promoter regions.