Despite the demonstrated increased cardiovascular (CV) risk associated with metabolic-dysfunction-associated fatty liver disease (MAFLD), genetic variants predisposing to MAFLD were not constantly associated with CV events. Recently, rs641738C>T near membrane-bound O-acyltransferase domain-containing 7 (MBOAT7) has been studied in MAFLD and CV outcomes. Therefore, we aimed to evaluate the association between rs641738C>T in the presence and severity of hepatic steatosis, fibrosis, biochemical markers and progression to hepatocellular carcinoma (HCC), in addition to CV outcomes in MAFLD. An electronic search on PubMed, Embase and Cochrane Library for articles published till 23 March 2020 was systematically performed. Articles were screened, and data extracted from eligible studies by two reviewers independently. Studies conducted on adults with MAFLD involving European, Hispanic and African American populations evaluating rs641738 reported reduced hepatic expression of MBOAT7, increased hepatic fat content, severity of MAFLD, susceptibility to develop NASH, advanced fibrosis and HCC in adults. However, most articles involving Asian individuals contradicted these findings. Studies involving obese children associated rs641738 with increased plasma alanine aminotransferase (ALT) levels, while its association with MAFLD remains inconsistent. The rs641738 variant was assessed as a MAFLD susceptibility gene in coronary artery disease (CAD) reporting neutral effects. Despite inconclusive results in Asian populations, rs641738C>T near MBOAT7 is associated with increased hepatic fat, MAFLD severity, susceptibility to develop NASH, advanced fibrosis and HCC in adults from Caucasian, Hispanic and African American ethnicities with MAFLD, as well as elevated ALT levels in children, while exerting neutral effects in CAD.