Abstract An oligoarray analysis was conducted to determine the differential expression of genes due to phenobarbital exposure in Drosophila melanogaster ( w 1118 strain) third instar larvae. Seventeen genes were observed to be induced with increased expression by a statistical analysis of microarrays approach with a q ≤ 0.05. At q ≤ 0.12, four more genes ( Cyp12d1, DmGstd4 , and two genes with unknown function) were found to be up‐regulated, and 11 genes with unknown function were found to be down‐regulated. Fifteen of these genes, Cyp4d14, Cyp6a2 , Cyp6a8 , Cyp12d1 , Cyp6d5 , Cyp6w1 , CG2065, DmGstd6, DmGstd7 , Amy‐p/Amy‐d, Ugt86Dd , GC5724, Jheh1, Jheh2 and CG11893, were verified using quantitative real time polymerase chain reaction. Some of these genes have been shown to be over‐transcribed in metabolically DDT‐resistant Drosophila strains.