This study aimed to examine the relationship between the therapeutic alliance developed by prospective psychological counselors with clients in their psychological counseling practices and their attachment styles and self-regulation skills. The study used a correlational survey model and was carried out on 460 prospective psychological counselors. Data were collected using the Psychological Counseling Form of the Therapeutic Alliance Scale, the Interpersonal Attachment Styles Scale, and the Self-Regulation Dimension of the Emotional Literacy Scale. After the normality analyses, the data collected in the study were analyzed with hierarchical regression. It was found that the attachment styles involved in the regression model in the first stage to predict the therapeutic alliance skills of psychological counselors had a significant contribution to the model (R = 0.42, R2 = 0.21, p<0.01). It was found that avoidant attachment style predicted therapeutic alliance more strongly than other attachment styles but that this predictive effect was negative ([beta]= -0.30, t = 7.50, p<0.01). The self-regulation skill involved in the model in the second stage of the regression analysis had a significant contribution to the model (R = 0.43, R2 = 0.22, p<0.01). In addition, it was found that self- regulation skills positively predicted therapeutic alliance ([beta] = 0.17, t = 3.17, p<0.05). According to the results of the study, it was found that awareness studies about attachment styles and self-regulation in the education of prospective psychological counselors affected their therapeutic alliance skills.