The frequency of deletional alpha-thalassaemia in a Javanese population sample (n = 103) was investigated at three restriction sites of the alpha-globin gene (BamHI, BglII and RsaI). The overall gene frequency of alpha+ deletional thalassaemia was found to be very low (0.03). Leftward (-alpha 4.2) and rightward (-alpha 3.7) deletions and triplicated genes were present in equal frequency (0.015 and 0.005, respectively).