There is currently little empirical evidence regarding how patients’ attachment patterns manifest in individual psychotherapy. This study compared the in-session discourse of patients classified secure, dismissing, and preoccupied on the Adult Attachment Interview (AAI). Rather than focusing on content or form alone, this study analyzed how patients’ discourse elicits and maintains emotional proximity with the therapist. The AAI was administered to 56 patients prior to treatment and one session for each patient was rated with the Patient Attachment Coding System (PACS) by four independent raters, blind to patients’ AAI classification. Significant differences were found in the discourse of patients with different attachment patterns. Namely, secure and preoccupied patients showed more contact-seeking behavior than dismissing patients, who avoided emotional proximity more, while preoccupied patients resisted therapists’ help more than did secure and dismissing patients. These results suggest that the different attachment patterns may have distinctive manifestations in the psychotherapy process that can be tracked by external observers.