摘要:BACKGROUND: One of the most important steps in increasing the nurses' professional competence and consequently improving the quality of nursing care is to evaluate nurses' clinical competency and then take effective actions to enhance it. This study aimed at exploring the clinical competence of Iranian nurses and factors related to it. MATERIALS AND METHODS: In this systematic review and meta-analysis, PubMed, Scopus, Web of Science, Scientific Information Database, and Iranmedex databases and Google Scholar search engine were searched to February 14, 2020. RESULTS: After screening, a total of 25 articles were included. In general, the level of clinical competence of Iranian nurses was at a desirable level. After meta-analysis of the mean score of nurses' clinical competence, the combined mean was 161.13 (95% confidence interval [CI]: 137.78–184.48; P < 0.001; I2 = 99.8%; P value for heterogeneity = P < 0.001) by the Competency Inventory for Registered Nurses (CIRN) questionnaire. The summarized mean of clinical competency measured by the Nurse Competence Scale (NCS) questionnaire was 70.75 (95% CI: 60.80–80.70; P < 0.001; I2 = 99.9%; P value for heterogeneity = P < 0.001). Factors affecting nurses' clinical competence were age ≥33 years, nursing work experience ≥9 years, and a master's degree in nursing. However, the clinical competence of nurses had a significant negative relationship with job stress. CONCLUSION: The level of clinical competence of Iranian nurses was desirable. Studies that used the CIRN, reported the highest and lowest clinical competence in clinical care and professional development dimensions, respectively. Studies that used the NCS, reported the highest and lowest clinical competence in dimensions of work role and ensuring quality, respectively.