Anopheles stephensi males were irradiated with 3.5 and 5.0 krad of X-rays to induce chromosomal aberrations. Late embryonic lethality scored as dark brown eggs gives a good indication for the presence of translocations. Three reciprocal translocations were isolated, [T(Y;21) 1, T(2.3) 2 and T(Y;3)3], from meiotic analysis of 90 out 129 families of backcrossed F, individuals with a sterility of above 30%.