Background: Serum prolactin levels are associated with metabolic disorders. However, the conclusions were inconsistent among published studies. Methods: PubMed, EMBASE, and the Cochrane Library were used to search for studies investigating the association between serum prolactin levels and metabolic disorders. Studies were included and reviewed if they reported the association between serum prolactin and metabolic components (including waist circumference, body weight indexes, blood pressure, blood glucose, blood lipids, insulin resistance, and type 2 diabetes). Results: A total of 14 studies were included in this systematic review. Evidence for certain associations between serum prolactin levels and body weight, blood lipids, blood glucose was insufficient, while some evidence showed a positive association between serum prolactin and blood pressure. High serum prolactin levels were found to be associated with lower risk of type 2 diabetes in women but not in men, but evidence for an exact correlation between serum prolactin and type 2 diabetes was insufficient. Conclusion: Evidence for associations between serum prolactin and metabolic profiles were insufficient. Higher serum prolactin levels might be associated with lower risk of type 2 diabetes in women. Further high-quality prospective studies are required.