The recent discovery of tiny microRNAs (miRNAs) has brought about awareness of a new class of regulatorsof diverse pathways in many physiological and pathological processes, such as tumorigenesis. They modulategene expression by targeting plethora of mRNAs, mostly reducing the protein yield of a targeted mRNA. Withaccumulation of information on characteristics of miR-205, complex and in some cases converse roles of miR-205in tumor initiation, progression and metastasis are emerging. miR-205 acts either as an oncogene via facilitatingtumor initiation and proliferation, or in some cases as a tumor suppressor through inhibiting proliferation andinvasion. The aim of this review is to discuss miR-205 roles in different types of cancers. Given the critical effectsof deregulated miR-205 on processes involved in tumorigenesis, they hold potential as novel therapeutic targetsand biomarkers.