BackgroundPostoperative rehabilitation after primary total hip arthroplasty (p-THA) differs between the Netherlands and Germany. Aim is to compare clinical effectiveness and to get a first impression of cost effectiveness of Dutch versus German usual care after p-THA.MethodsA transnational prospective controlled observational trial. Clinical effectiveness was assessed with self-reported questionnaires and functional tests. Measurements were taken preoperatively and 4 weeks, 12 weeks, and 6 months postoperatively. For cost effectiveness, long-term economic aspects were assessed from a societal perspective.Results124 working-age patients finished the measurements. German usual care leads to a significantly larger proportion (65.6% versus 47.5%) of satisfied patients 12 weeks postoperatively and significantly better self-reported function and Five Times Sit-to-Stand Test (FTSST) results. German usual care is generally 45% more expensive than Dutch usual care, and 20% more expensive for working-age patients. A scenario analysis assumed that German patients work the same number of hours as the Dutch, and that productivity costs are the same. This analysis revealed German care is still more expensive but the difference decreased to 8%.ConclusionsGerman rehabilitation is clinically advantageous yet more expensive, although comparisons are less straightforward as the socioeconomic context differs between the two countries.Trial registrationThe study is registered in the German Registry of Clinical Trials (DRKS00011345, 18/11/2016).Supplementary InformationThe online version contains supplementary material available at 10.1186/s12891-023-06654-w.