Randomized clinical trials represent the final, essential link between basic medical research and human health. However, their conduction presents very complex ethical problems, since the patient is the actual target of the experiment. Proper randomization, informed consent, and preliminary disclosure of results create deep ethical conflicts between the role of caretaker and that of impartial observer, both played by the same doctor. The dilemma reproduces the conflict between two different ethics. One is based on the inalienable individual rights stemming from the concept of man as an end in himself and not a means to an end. The other, derived from utilitarian philosophies, is based on the benefit for society as a whole. If we agree that randomized clinical trials represent the best method to test the validity of a new treatment, there is no easy solution. The dilemma could be solved by separating the role of the family doctor, committed to the best treatment possible for his patient, from the role of the scientist, committed to the progress of science and humanity. The former is involved in the treatment of individual patients, the latter in clinical and scientific experiments of a therapeutic nature. The patient may trade his rights to the best possible cure for the safety and the efficiency guaranteed by the scientific institution conducting the trial. Trials on relevant issues--expected to produce important results and impeccably designed scientifically--could be endowed with the ethics of science per se and this could be considered equivalent to the individual rights waived by the patient.