Sperm chromosome complements from two males, one heterozygous for the reciprocal translocation t(2;17)(q35;p13) (n = 18) and one for t(3;8) (p13;p21) (n = 73), were analyzed. Only 2:2 segregations were observed with t(2;17): alternate, 56%; adjacent-I, 33%; adjacent-II, 11%. Both 2:2 and 3:1 meiotic segregations occurred in t(3;8): alternate, 34.2%; adjacent-I, 43.8%; adjacent-II, 20.5% and 3:1, 1.4%. A significant excess of chromosomally normal versus balanced sperm complements was observed with both translocation heterozygotes. The frequencies of other chromosome aberrations unrelated to the translocations were 16.7% for t(2;17) and 8.2% for t(3;8). The ratio of X-bearing to Y-bearing sperm was not different from the theoretically expected ratio of 1:1.