Using nested-PCR amplification of honeybee cDNA with degenerate primers derived from mammalian sequences, we have cloned four DNA fragments from putative odour receptor genes. This conclusion is based on high amino acid sequence similarity with published sequences from vertebrates and hydrophilicity profiles in agreement with including these genes in the super family of seven transmembrane domain receptor genes. These results are discussed in the context of the evolution of the olfactory receptor genes.