Purpose: The purpose of this study is to clarify the relationship between two sub-constructs of heavy work investment--work engagement and workaholism. Design/methodology/approach: The authors conducted a systematic review and meta-analysis to synthesize and critically assess existing research on the relationship between these concepts. Findings: The review revealed three major shortcomings of the extant literature: a dichotomous perspective, variations in measurements and the unaddressed complexity of the relationship. Originality/value: Based on these findings, this study provides a discussion on the limitations and suggestions for future research on work engagement and workaholism, including using a person-centered approach.