Mindfulness is a quality of consciousness that consists of purposeful attention to and awareness of the present moment, approached with an attitude of openness, acceptance, and nonjudgment. Research evidence shows that mindfulness has positive effects on mental health and psychological well-being, physical health, and quality of intimate relationships. However, few researchers have studied the effects of mindfulness in a work setting. In this project, I expanded previous research by exploring how mindfulness, as developed in a mindfulness-based training program, affects the workplace outcomes of performance and citizenship behavior. I proposed that these effects are mediated through the positive effects of mindfulness on one’s experienced affect and one’s work relationships. I also examined interdependence as a moderator of the relationship quality-work outcomes relationship. The research study employed an experimental group of participants in a mindfulness-based program and a nonequivalent control group to test the specific hypotheses. Data were provided by multiple sources: mindfulness, affect, and role interdependence by study participants; relationship quality by coworkers; performance and citizenship behavior by supervisors. Analytic strategy was comprised of correlational analysis and regression as well as analytical procedures for moderated mediation. The mindfulness-based programs were effective in increasing mindfulness, particularly for those participants who were lower in mindfulness prior to program participation. Participants also experienced improved affect. However, the proposed model relating mindfulness to work outcomes was not supported. Mindfulness was significantly related to positive and negative affect as predicted; however, mindfulness was not significantly correlated with relationship quality or job performance. Its significant relationship with citizenship behavior was in the opposite direction as hypothesized. In the full model, coefficients for mindfulness, experienced affect, relationship quality, and role interdependence in the prediction of job performance and citizenship behavior were not significant. Additionally, interdependence did not interact