In recent years, the role of microRNAs (miRNAs) in disease has attracted considerable interest, underscoring their potential utility as diagnostic biomarkers. miR‑100, belonging to the miR‑99 family, is integral to the pathophysiological processes underlying numerous diseases. miR‑100 has been found to influence the pathogenesis of a variety of noncancerous diseases. As for cancer, this factor plays a significant role in various tumors throughout diverse systems, influencing essential processes including cell proliferation, invasion, migration and apoptosis of cancerous cells. This review examines the existing literature on miR‑100 in the context of non‑cancerous diseases and cancer, investigates its mechanisms of action across different diseases and considers its potential role as a diagnostic biomarker as well as its involvement in cancer drug resistance.