Precarious employment has expanded during the last decades, but there is no full consensus on its definition, and its impact on mental health is not completely understood. The relevance of several micro- and macro-level variables in the association between precarious employment and mental health has not been fully addressed. This review has 2 aims: to identify scientific evidence on the relationship between various dimensions of precarious employment and mental health, and to synthesize the inclusion of a gender-sensitive perspective, context variables, workers’ household variables, and the discussion of causal mechanisms underlying the association. The literature was searched in PubMed, EMBASE, Web of Science and PsycINFO including articles dated 2010–May 2018. A minimum of 2 independent reviewers assessed each article regarding quality and eligibility criteria. The search retrieved 1522 papers, of which 54 (corresponding to 53 studies) met the inclusion criteria. Most of the studies analyzing job insecurity, temporariness and multidimensional approaches reported a significant association. Nevertheless, results for working time arrangements and downsizing are inconclusive. Around half of the studies included sex-stratified analyses and formulated contradictory conclusions. Overall, 7 studies considered workers’ household situation and only 3 delivered significant results, and 16 described some of the potential pathways. There is evidence of an association between various precarious employment approaches and mental health problems. Further research (preferably longitudinal) should aim to discuss theoretical models explaining the pathways between precarious employment and mental health, including a gender-sensitive perspective, and integrating several levels of individual and contextual variables. Int J Occup Med Environ Health. 2020;33(5):569–98