A peripheral blood smear review is a standard test used to diagnose both hematologic and non-hematologic illnesses. An expert's evaluation of a peripheral smear allows for a broad examination of blood cell morphology and may identify metabolic, nutritional, genetic, and inflammatory problems, as well as hemolysis, blood-borne parasites, and neoplasia. Literature review among previous published studies up to November, 2021, carried out to reach the concept of indication for peripheral blood smear. In contrast, smears requested to evaluate anemia and thrombocytopenia, the most common reasons for peripheral smear review requests, had lower rates of potential clinical value, aside from confirming the absence of significant findings.