Rapid changes in workplace (e.g., technology, organizational structure) increase the complexity of work which, in turn, increases the demand for continual learning. Current training efforts, in which organizations sponsor employee training in some form, are insufficient in meeting this demand for training. As a result, organizations have embraced the principles of self-directed learning (SDL) and encouraged employees to assume some responsibility for their own learning. Yet, the effectiveness of SDL in the workplace has received little empirical attention. Previous research has demonstrated that individuals high in SDL readiness (i.e., individuals who prefer guiding and directing their own learning as opposed to a teacher-centered format) received higher overall performance ratings. However, researchers have not examined the effect of actual SDL experience on either overall performance or performance in the specific area related to those SDL experiences. While it has been maintained that SDL is an effective form of workplace training to improve job performance, this assumption has not been tested. The goal of the present research was to test this assertion by evaluating a SDL program (i.e., an on-line listening skills course) currently in place. Measures of individuals' SDL readiness, work locus of control, cognitive ability, SDL activities, learning acquisition, and job performance were examined before and after engaging in the SDL program. A control group was secured for comparison, thereby providing a better test of the propositions. Results supported many of the proposed relationships. In particular, SDL readiness and work locus of control predicted membership in the target SDL course and the extent to which participants engaged in the course. Participation in the listening skills course and the extent to which they engaged in the course predicted greater learnings, which in turn predicted improved listening skills performance three months after the completion of the course. Implications of the results as it relates to past research, limitations of the study, and directions for future research are discussed.