Some pyrido [1, 2-a] benzimidazoles were prepared in order to investigate their in vitro antineoplastic and anti-HIV activities. Two compounds (9b, NSC 658526 and 15, NSC 664715) showed a variable degree of antineoplastic activity against some of the cell lines tested. Compound 9a (NSC 649900) exhibited a good in vitro antineoplastic activity with subpanel disease selectivity, particularly against most of the cell lines of leukemia and ...