Objectives There are many studies about Iranian clinical pharmacists' interventions and their impacts on medication safety and cost. The aim of this study is to collect data and critically evaluate the clinical and economic effects of Iranian clinical pharmacist interventions and activities. To our best of knowledge, this research is the first review of publications about Iranian clinical pharmacists' interventions and activities. Evidence acquisition. Six online databases, including PubMed, Scopus, Medline, Cochrane Central Register of Controlled Trials, Cochrane Database of Systemic Reviews, and Google Scholar were searched using the terms 'BIranian^, Bclinical pharmacist^, 'adverse drug reactions^, Bmedication errors^, Bdrug interaction^, Bdrug utilization evaluation^, Bcost^, and Binterventions^for English studies conducted in Iran and described clinical pharmacist-initiated interventions, published before December 2018. The search and extraction process followed PRISMA guidelines. Observational or retrospective studies, clinical trials, congress abstracts, and case reports or case series were excluded. The search strategy after full-text review identified 39 articles matching the eligibility criteria. Results Thirty-nine articles were recruited. They included establishing pharmaceutical care in outpatient clinics and drug information centers (n = 4); prevention, detection, and management of adverse drug reactions(n = 4), designing protocols and improving drug utilization pattern(n = 16), prevention, detection, and management of medication errors (n = 11), and all clinical pharmacist services(n = 4). Most clinical pharmacist interventions and activities were regarding designing protocols, improving drug utilization pattern, as well as detection, prevention, and management of medication errors. About three-fourth (74.35%) of included studies were from either ambulatory care or in-patient settings in Tehran. The median (interquartile range) duration of intervention as well as follow-up phases was 9 (5) months. Conclusion Data of our review support the beneficial role of clinical pharmacists in the improvement of quality, safety, and efficiency of patients' pharmaceutical care in Iran.