OBJECTIVE: Older persons living with HIV (PLWH) disease commonly experience failures of time-based prospective memory (PM) in their daily lives. This study examined the benefits of providing strategic supports at encoding, monitoring, and cue detection for naturalistic time-based PM among older PLWH. METHOD: Participants included 116 older PLWH and 48 seronegatives who completed a baseline neuropsychological evaluation (see Woods et al., 2020), including a laboratory PM experiment that paralleled the design of the current naturalistic study. The naturalistic time-based PM task required participants to press a button on a portable PM response box 4 times per day for 1 month. PLWH were randomly assigned to an unsupported control condition or to an experimental group in which strategic processing was supported at encoding (implementation intentions and visualization), monitoring (content-free cuing), and/or cue detection (auditory alarm). The seronegative participants were all assigned to the unsupported control group. RESULTS: In a model adjusting for age and affective disorders, PLWH who received all three supports in combination demonstrated moderately better naturalistic time-based PM accuracy as compared with PLWH controls. Both the cue detection and combination conditions were associated with markedly more precise response timing on the naturalistic time-based PM task. Supported PM accuracy as measured in the laboratory was positively associated with naturalistic PM accuracy among PLWH in the experimental groups. CONCLUSIONS: Providing strategic supports to enhance the cue salience of naturalistic time-based PM tasks may improve both the accuracy and timing with which older PLWH remember to perform time-based intentions. (PsycInfo Database Record (c) 2021 APA, all rights reserved).