Degenerate primers to the kinesin motor domain were used in the polymerase chain reaction to amplify DNA sequences from Drosophila genomic DNA and cDNA libraries. The amplified DNA sequences were hybridized to polytene chromosomes and the map positions of the hybridizing sites were determined. More than 30 sites of hybridization were detected, indicating that the kinesin gene family may be much larger than previously thought. One new family member has already been identified as a result of this screen. The map positions should aid in the identification of further kinesin family members. Some of these kinesin-related genes are anticipated to function in previously undiscovered roles in the cell.