A balanced discussion on the ethics of randomized clinical trials should not be based on a single ethical aspect such as respect for the patient's autonomy. Rather, the analysis should consider the four ethical principles-respect for autonomy, non-maleficence, beneficence, and justice-as applicable to all groups of persons concerned. We present the ethical benefits and costs of the present practice of randomized clinical trials for four groups: patients involved in clinical trials, patients not involved in trials, participating physicians and society. The ALARA (As Low As Reasonably Achievable) approach is then introduced and practical measures to achieve a positive balance between ethical benefits and costs of randomized trials are proposed.