Introduction: It is unclear whether rehabilitation with the use of an exercise program can be an alternative to surgery in distal radioulnar joint instability resulting from injuries of the triangular fibrocartilage complex. The purpose of this study was to gain insights into the feasibility and effects in reducing pain and functional limitations by using distal radioulnar stability training. Methods: A prospective pilot cohort intervention study was used including patients with a triangular fibrocartilage complex Palmer 1B lesion and distal radioulnar joint instability. The primary objective was the reduction of pain and functional limitations as measured by the Patient-Rated Wrist-Hand Evaluation. Secondary objectives were to assess number of surgical interventions, treatment sessions, and patient satisfaction. Results: Twenty-one patients (mean age: 33.2 years) were included with a median time of symptom onset of eight months (IQR: 5-24). The distal radioulnar stability training program showed a clinically relevant positive change in the Patient-Rated Wrist-Hand Evaluation total and subscale scores when compared to the baseline assessment. Six patients opted for surgical intervention at six months follow-up, and two patients were considering surgery at the long-term follow-up. Conclusion: Rehabilitation with stabilizing exercises in patients with distal radioulnar joint instability caused by triangular fibrocartilage complex 1B lesions provides pain relief and increases function. Findings should be validated by further controlled prospective studies.