The concept of boundaryless careers characterizes emerging career patterns that are less dependent on traditional organizational career management. Based on an evidence-based review of literature on the relationship between career boundarylessness and career success published from 1994 to 2018, we found that boundaryless careers have mixed effects on the various indictors of career success, and these effects depend on the operationalization of career boundarylessness, the motives (voluntary vs. involuntary), career competencies, adaptive capabilities and career resources held by individuals, as well as the structural constraints and institutional support for boundary-crossing behaviors. In addition, career success was also found to predict subsequent career mobility. Based on these findings, we develop an integrative model to understand the complicated and dynamic relationship between boundaryless careers and career success. This review serves as an important step to integrate theories and research on boundaryless careers and career success, and more interdisciplinary work should be done in the future to examine this question.