The assessment of students nursing competence is an issue of interest worldwide. Nursing competency includes core abilities that are required for fulfilling one’s role as a nurse. The following databases were included in the search strategy: (Ovid databases (including Medline, Embase, PsycINFO, and HealthSTAR) (ISI, SCOPUS, ProQuest, Iranmedex, Google Scholar, PubMed) and Persian (Scientific Information Database) databases. The researcher assessed the eligibility of the study by title, abstract, full-text and assessed the methodological quality of the included studies and then analyzed the study findings literal synthesis approach. The initial search yielded 142 results and twelve reviews were finally included following critical appraisal and met the inclusion criteria and were included in this review. The nursing student competency was defined as a general students' nursing competence commonly compromise twelve components as; patient-centered care, communication, evidence-based practice and research, critical thinking and innovation, personal traits, quality of practice, collaboration, professional practice evaluation, management of nursing care, resource utilization and legal and ethical practice. Seven nursing student competency levels were identified. Despite the current systematic review of nursing student competency, its components and levels, the need for further research to reform nursing student competency, components, and levels is required