People with multiple sexual partners forget a significant proportion of their partners, and drug injectors forget a large proportion of the persons with whom they inject drugs (Brewer, Garrett, & Kulasingam, 1999). This incomplete reporting poses a problem to partner notification and social network research on infectious diseases. We evaluated supplementary interviewing techniques to enhance recall of sexual and injection partners in 158 persons at high risk for HIV. After subjects finished recalling their partners on their own, interviewers administered one of five techniques to elicit additional partners who might have been forgotten. Four experimental techniques involved cues (locations, role relationships, personal timeline, and partners recalled prior to cues) developed from research on how partners are organized in memory. Alphabetic cues served as a control technique. Each technique elicited additional partners for at least some subjects, although the techniques varied moderately in their effectiveness and time efficiency. To assess the techniques' cumulative effects, we administered all five techniques to 19 subjects. The combined techniques increased the number of sexual and injection partners elicited by 40% and 123%, respectively, on average. The techniques were most effective with individuals who recalled many partners before the cues and/or sensed they may be forgetting partners. Multiple lines of evidence indicate that the cue-elicited partners are as valid as partners recalled before the cues. Cue-elicited partners also do not differ substantially from partners recalled before the cues on epidemiologically significant variables. These results suggest that the supplementary techniques can be used to counteract forgetting appreciably.