BackgroundElectronic health (eHealth) programs have been found to be effective in treating many psychological conditions. However, regarding borderline personality disorder (BPD), only a few eHealth programs have been tested, involving small interventions based on the dialectical behavior therapy treatment approach. We investigated priovi, a program based on the schema therapy (ST) approach. priovi is considerably more comprehensive than prior programs, offering broad psychoeducation content and many therapeutic exercises.ObjectiveWe tested the acceptability and feasibility of priovi in 14 patients with BPD as an add-on to individual face-to-face ST.MethodsPatients received weekly individual ST and used priovi over a period of 12 months. We assessed BPD symptom severity using self-reported and interview-based measures. Qualitative interviews were conducted with both patients and therapists to assess their experiences with priovi.ResultsBPD symptoms improved significantly (Cohen d=1.0). Overall, qualitative data showed that priovi was positively received by both patients and therapists. Some exercises provoked mild anxiety; however, no serious threat to safety was detected.Conclusionspriovi is a potentially helpful and safe tool that could support individual ST. It needs to be further tested in a randomized controlled study.Trial RegistrationGerman Clinical Trials Register DRKS00011538; https://www.drks.de/drks_web/navigate.do? navigationId=trial.HTML&TRIAL_ID=DRKS00011538 (Archived by WebCite at http://www.webcitation.org/74jb0AgV8)