This study investigates the genetic variation and tolerance to ethanol and acetic acid in nine Indian populations of *Drosophila melanogaster* collected along a 20°N latitudinal range. The results show significant clinal variation at the alcohol dehydrogenase (*Adh*) locus, with the frequency of the *Adh*^F^ allele increasing significantly with latitude (0.036 ± 0.004 per degree of latitude; genetic divergence *F*ST = 0.25). Adult individuals from these populations also exhibited parallel patterns of latitudinal ethanol and acetic-acid tolerance, with northern populations showing higher tolerance to higher concentrations of these compounds compared to southern populations. The observed genetic divergence at the *Adh* locus and in ethanol and acetic-acid tolerance is attributed to balancing natural selection varying spatially along the north-south axis of the Indian subcontinent. The study highlights the importance of environmental gradients in shaping adaptive traits and supports the hypothesis that natural selection maintains such clinal allozymic variation.This study investigates the genetic variation and tolerance to ethanol and acetic acid in nine Indian populations of *Drosophila melanogaster* collected along a 20°N latitudinal range. The results show significant clinal variation at the alcohol dehydrogenase (*Adh*) locus, with the frequency of the *Adh*^F^ allele increasing significantly with latitude (0.036 ± 0.004 per degree of latitude; genetic divergence *F*ST = 0.25). Adult individuals from these populations also exhibited parallel patterns of latitudinal ethanol and acetic-acid tolerance, with northern populations showing higher tolerance to higher concentrations of these compounds compared to southern populations. The observed genetic divergence at the *Adh* locus and in ethanol and acetic-acid tolerance is attributed to balancing natural selection varying spatially along the north-south axis of the Indian subcontinent. The study highlights the importance of environmental gradients in shaping adaptive traits and supports the hypothesis that natural selection maintains such clinal allozymic variation.