Community pharmacists are responsible for providing the appropriate information on the use of medications to patients, which may enhance their medication adherence. The extent of control that patients have on their health care preferences creates many challenges for community pharmacists. This study aimed to determine the impact of pharmacist interventions and patient decisions on health outcomes concerning medication adherence and the quality use of medicines among patients attending community pharmacies. Appropriate studies were identified in a systematic search using the databases of Medline, Scopus, Google Scholar, and PubMed. The search included literature published between 2004 and 2019. The database searches yielded 683 titles, of which 19 studies were included after the full-text analysis with a total of 9313 participants. Metaprop command in Stata software version 14 was used for the analysis. This study was undertaken based on the general principles of the Cochrane Handbook for Systematic Reviews of Interventions and subsequently reported according to the Preferred Reporting Items for Systematic Reviews (PRISMA) extension. The Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach was directly used to rate the quality of evidence (high, moderate, low, or very low). The results revealed the effective interaction between patients and community pharmacists, the importance of pharmacist intervention on medication adherence and quality use of medicine, and the role of community pharmacists in counselling patients. Decision/choice of patients in self-care and self-medication is a factor contributing to health outcomes. Effective interaction of community pharmacists with patients in terms of medication adherence and quality use of medicines provided a better health outcome among patients. The community pharmacists influenced the decision/choice of patients in self-care and self-medications.