BackgroundAccording to European clinical research legislation, no undue influence, including financial incentives, should be used to encourage participation in clinical trials. Financial compensation should be based on the inconvenience experienced by patients and is determined by the sponsor.ObjectivesThe objective of this study was to assess the adequacy of patients' financial compensation by obtaining an external ethical opinion compared to the actual compensation provided.MethodsWe randomly selected and reviewed 50 clinical drug trials, including 25 academic and 25 industry‐sponsored studies. An external ethics group consisting of three members from French ethics committees, blinded to the actual compensation and the sponsor, retrospectively reviewed the study characteristics and assessed whether financial compensation was appropriate. Cohen's Kappa test measured agreement between actual compensation and the ethics group's opinion, and the McNemar test measured discrepancies.ResultsThere was no agreement between the actual financial compensation and the ethics group's opinion (K = −.07; 95% CI = [−.16–.02]). More discrepancies were found in favour of financial compensation according to the ethics group than provided by sponsors (12 vs. 2, p = .016). The ethics group recommended financial compensation in 12 out of 50 studies (24%), which were studies with a higher number of additional visits (p = .004) and were more frequently sponsored by industry (p = .008). Sponsors only provided financial compensation in 2 out of 50 studies (4%).ConclusionPatients are rarely compensated despite the perceived inconvenience. Both sponsors and ethics members struggle to determine the need for financial compensation, indicating a need for more precise recommendations for both parties.