Professional counselors have the task of helping individuals cope with a vast range of mental health and developmental issues. In 2015, approximately 43 million Americans over the age of 18 had experienced a mental health issue within the past year (SAMHSA, 2015). Recognizing that there are a growing number of mental health counselors entering the field each year (CACREP, 2016; U.S. Department of Labor, 2017), it is important that counselor training programs take steps to ensure that trainees are prepared to provide competent counseling services. Researchers and scholars (Auxier, Hughes, & Kline, 2003; Greason & Cashwell, 2009; Skovholt & McCarthy, 1988; Skovholt & Ronnestad, 2003) have determined many factors that influence counselor development. One such factor, counselor self-efficacy (CSE), seems imperative to counselor development (Goreczny, Hamilton, Lubinski, & Pasquinelli, 2015; Kozina, Grabovari, De Stefano, & Drapeau, 2010; Larson & Daniels, 1998; Lent et al., 2009; Lent, Hill, & Hoffman, 2003). Further, attachment anxiety and avoidance may be important in the development of CSE. Accordingly, it is important to understand the influence of attachment anxiety and avoidance on trainee’s counselor self-efficacy during training because trainees with elevated attachment-related anxiety and/or avoidance may experience negative consequences on their development as counselors. Mindfulness training however, may be key to increasing CSE and buffering the effects of attachment anxiety and/or avoidance. Researchers have examined the relationship between attachment and counselor self-efficacy (Marmarosh et al., 2013; Smothers, 2009), mindfulness and counselor self-efficacy (Greason & Cashwell, 2009), and attachment strategies and mindfulness (Caldwell & Shaver, 2013; Davis, Morris, & Drake, 2016; Walsh, Balint, Smolira, Fredericksen, & Madsen, 2009). To date, however, researchers had not considered how the three may interact. The purpose of this study was to address an important gap in the counselor training literature by examining whether mindfulness moderates the relationships between attachment-related anxiety and avoidance and CSE among trainees. The researcher implemented a correlational design, using multiple regression and multiple regression with the interaction term in order to explore the relationships among attachment anxiety, attachment avoidance, mindfulness, and counselor self-efficacy. Bivariate correlations were found among several of the variable including mindfulness and CSE, attachment avoidance and CSE, mindfulness and attachment anxiety, and mindfulness and attachment avoidance. Although mindfulness did not emerge as a predicted moderator variable findings from this study support previous researchers findings that mindfulness is related to CSE. Implications for counselor educators and counselor trainees are discussed