This study identified variables associated with increased condom use among drug abusers in a randomized trial of three AIDS educational programs in a short-term inpatient detoxification program. Participants (n = 301) completed baseline and follow-up interviews and were heterosexually active on both occasions. At baseline, 10% always, 24% sometimes, and 66% never used condoms, and this distribution changed only slightly at follow-up. Among the latter two groups, 21% increased their use. There was no differential intervention effect on changes in condom use. Women, but not men, were more likely to initiate condom use than to increase to consistent use with all partners, and to initiate use if they had multiple partners. Although beneficial attitudes and beliefs about condoms were more common among women at baseline, positive changes in these attitudes/beliefs were associated with increased condom use among men only. Among men, personal attitudes and beliefs were associated with increased condom use, while among women, perceptions of the attitudes of sexual partners were more important.