Association of DDT resistance levels with chromosome inversion polymorphism was investigated in Anopheles arabiensis samples collected from southwestern Ethiopia. The frequencies of the 2Ra, 2Rd, and 3Ra inversions in 1988 and 1990 between the DDT survivors pooled from the 3 times of exposure and unexposed controls did not differ significantly. However, for 2Rb a significant association was observed (Mantel-Haenszel chi 2, stratified for year of collection = 10.4, P < 0.001). The inversion frequency was 56% among unexposed individuals, but it was 64-92% among those surviving exposure.