Objective: The aim of this study was to investigate a sequence of associations between clients' pretreatment attachment style, the development of individuated-secure attachment to the therapist (i.e., therapeutic attachment), and the experience of increased comfort with emotional closeness (growing engagement) or independence (growing autonomy) in therapy. Moreover, the study explored whether clients' experience of growing engagement or growing autonomy was associated with a change in interpersonal problems at the end of therapy. Method: Three hundred thirty adult clients (mean age 40.2, 75% female) were seen by 44 therapists in individual psychotherapy. The associations between pretreatment attachment insecurity measured on the Experiences in Close Relationships scale, repeated measures of therapeutic attachment measured on the Client Attachment to Therapist Scale, repeated measures of a growing engagement or growing autonomy measured on the Therapeutic Distance Scale, and pre-post measures of interpersonal problems measured on the Inventory for Interpersonal Problems were analyzed using multilevel modeling. Two types of therapeutic attachment were estimated, one controlling for anxious attachment characteristics and one for avoidant. Results: Significant associations between higher levels of therapeutic attachment controlled for avoidant attachment characteristics and lower levels of growing autonomy in therapy were found. Moreover, higher levels of growing engagement in therapy and higher levels of therapeutic attachment controlled for anxious attachment characteristics were associated with a decrease in interpersonal problems at the end of therapy. Conclusions: Distinct types of therapeutic attachment may exert different influences on the process and outcome of therapy. Furthermore, therapists' attunement to clients' specific attachment needs in therapy may enhance interpersonal outcomes of treatment.