Drug-related problems in older people during care transitions have become a major public health problem since they threaten patient safety. The objective of our paper is to investigate the extent and frequency of drug-related problems (discontinuity, adherence, errors, interactions and adverse events) after hospital discharge and the efficacy of interventions intended to reduce them. We included 20 studies in the review. All of them underlined the high frequency and complexity of drug-related problems in older people after hospital discharge. Interventions proposed to improve care transitions led to diverse and sometimes contradictory results, but the findings suggested that combining hospital discharge measures with home follow-up strategies is of value. We conclude that it is not possible to estimate the frequency of drug-related problem through a review of selected articles or to evaluate the efficacy of the proposed interventions. More research is needed in this field to reduce uncertainty and generate evidence-based recommendations for physicians.