BACKGROUND: Despite several decades of evidence supporting the benefits of taking medications in various diseases and healthcare settings, a significant proportion of prescribed treatments are not taken. This review sought to synthesise qualitative research exploring experiences of medication taking around the world, and to determine whether there were consistent messages arising from these studies. METHODS AND FINDINGS: 5 databases (MEDLINE, PsycINFO, EMBASE, SCOPUS, CINAHL) were systematically searched to identify published research papers using qualitative methodologies, which explored medication-taking experiences in patients, citizens, carers, relatives and clinicians. Data were extracted independently by at least two clinician reviewers. Implications for practice from individual papers were charted and coded using thematic content analysis. These were then cross-tabulated with research paper categories to explore emergent patterns with particular implications for practice. 192 papers from 34 different countries were included in the review. Implications for practice fitted into 11 categories: increase family involvement, increase clinician involvement, promote personalised management, address practical barriers, provide ongoing support, promote self-management, adopt a patient-centred approach, improve patient education, address system barriers, increase access to non-prescribing clinicians and improve clinician training. These implications for practice were generally evenly spread across research paper categories. CONCLUSIONS: Implications for practice from the published qualitative literature exploring medication-taking are notably consistent across research methods, disease categories and geographical settings. More recent clinical trials of interventions to improve adherence have started to draw on these findings by focussing on improving clinical interactions and involving patients in healthcare decisions. Promoting patient education and self-management have been widely advocated, and improvements at a system level have been frequently cited in studies from developing countries and those relating to communicable diseases. Regardless of the setting, clinicians and policymakers around the world can focus efforts to improve medication-taking by considering a number of consistently emerging findings.