Dialectical behavior therapy (DBT) and dynamic deconstructive psychotherapy (DDP) are listed in the National Registry of Evidence-Based Programs and Practices based on their performances in randomized controlled trials. However, little is known about their effectiveness in real-world settings. In the present study, the authors observed the naturalistic outcomes of 68 clients with borderline personality disorder (BPD) who were treated at a medical university clinic by experienced therapists using either comprehensive DBT (n = 25) or DDP (n = 27), with 16 clients treated with unstructured psychotherapy serving as a control. We found both DBT and DDP achieved significant reductions in symptoms of BPD, depression, and disability by 12 months of treatment, and showed effect sizes consistent with controlled trials. However, attrition from DBT was high and DDP obtained better outcomes than DBT (d = .53). Larger effectiveness studies are needed to replicate these findings, delineate common and unique treatment processes, and determine therapist and patient characteristics predicting positive outcomes.