OBJECTIVES (1) To collect, analyze and synthetize the evidence on muscle dysmorphia diagnosis as defined by Pope et al. and (2) To discuss its appropriate nosology and inclusion as a specific category in psychiatric classificatory systems. METHOD A systematic search in the MEDLINE, the PsycNET, the LILACS and SciELO databases and in the International Journal of Eating Disorders was conducted looking for articles published between January 1997 and October 2014 and in EMBASE database between January 1997 and August 2013. Only epidemiological and analytical studies were considered for selection. The methodological quality of included studies was assessed according to the Evidence-Based Mental Health and the National Health and Medical Research Council's guidelines. The support for inclusion of muscle dysmorphia in psychiatric classificatory systems was examined against Blashfield et al.'s criteria. RESULTS Thirty-four articles were considered eligible out of 5136. Most of the studies were cross-sectional and enrolled small, non-clinical samples. The methodological quality of all selected papers was graded at the lowest hierarchical level due to studies' designs. Forty-one percent of the publications considered the available evidence insufficient to support the inclusion of muscle dysmorphia in any existing category of psychiatric disorders. The current literature does not fulfill Blashfield et al.'s criteria for the inclusion of muscle dysmorphia as a specific entity in psychiatric diagnostic manuals. CONCLUSION The current evidence does not ensure the validity, clinical utility, nosological classification and inclusion of muscle dysmorphia as a new disorder in classificatory systems of mental disorders.