BackgroundDiaphragm plication remains the only effective treatment for diaphragm paralysis. Robot-assisted thoracoscopic (RATS) diaphragm plication combines advantages of open and thoracoscopic techniques. We present our experiences focussing on lung-function improvement and surgical outcome.MethodsIn this single-center retrospective study with comparative analysis, perioperative data of all patients who underwent RATS or thoracoscopic (VATS) diaphragm plication between 2015 and 2022 at our institution were assessed. Functional outcome was analysed with pre- and postoperative pulmonary function tests in sitting and supine position.ResultsWe included 43 diaphragm plications, of which 31 were performed via RATS. Morbidity in the RATS- and VATS-cohort were 13 and 8%, respectively (p= 0.64), without any major complication (Clavien-Dindo ≥ III, 0%). Surgical time for RATS diaphragm plication was reduced drastically with a median operating time for the first 16 patients of 136 min (range 84–185) and 84 min (range 56–122) for the most recent 15 patients (p< 0.0001). Pulmonary function testing after RATS-plication showed a mean increase in vital capacity (VC) of 9% (SD 8,p< 0.0001) and of 7% (SD 9,p= 0.0009) in forced expiratory volume in 1 s (FEV1) when sitting and 9% (SD 8,p< 0.0001) for VC as well as 10% (SD 8,p= 0.0001) for FEV1 when in supine position.ConclusionRATS diaphragm plication is a very safe and feasible approach, yielding good results in improving patients’ pulmonary function. Further studies are required to elucidate possible advantages over VATS or open approaches.Graphical abstract