The somatic karyotype ofDrosophila jambulina includes three pairs of V-shaped and one pair of rod-like chromosomes in the female, whereas one red is replaced by a J-shaped element in the male. The salivary chromosome complement comprises five long and one extremely short arms radiating out from a chromocentre. The photomap of salivary gland chromosomes has been prepared and the important identifiable landmarks described. From a sample of 130 wild females studied, 79 heterozygous paracentric inversions of 29 types and four deletions of three types have been detected, thus demonstrating that this species is highly polymorphic.