Globally, in-home drug-storage compliance is often unsatisfactory, especially among older adults, and can lead to negative health outcomes. This study used a cross-sectional and descriptive design to examine in-home drug-storage compliance among older adults. Convenience sampling was used to recruit 117 older adults in Hong Kong. An in-home drug-storage checklist was used to assess the in-home drug-storage environments (light, temperature, and humidity) and drug-storage methods (drug safety, packaging, information, and expiration) of each older adult. The findings showed that Hong Kong older adults’ overall compliance rate in drug storage was 87.25%, and their compliance rate for drug-storage methods (84.59%) was lower than that for drug-storage environments (97.02%). Older adults who were of advanced age, who were less educated or who lived alone demonstrated lower in-home drug-storage compliance. This indicates the need to revise existing health-education strategies to encourage in-home drug-storage compliance. Healthcare professionals should assess older adults’ drug-storage compliance to identify less compliant subgroups and deliver specific drug-storage support as required. Family members should also be involved in this process.