Conflicts of interest are frequent in medical practice. They occur when a secondary interest unduly influences professional medical judgment, over and above the patients' benefit, his first real interest. Most of these secondary interests come from particular businesses of the physicians or their relationships with the industry. They may become a threat to the confidence that is established in the patient-physician relationship or to the medical profession as a whole. These conflicts of interest vary in types and magnitude and are not recognized by physicians on most occasions. Solutions are inevitably related to the honesty and integrity of each physician. Due to the absence of specific national ethical references, it is necessary to discuss the issue and conclude recommendations that guide interns, residents, clinicians, researchers, medical educators, medical and scientific associations to resolve these types of conflicts (Rev Méd Chile 2003; 131: 1463-8).