Many studies examine a stressors-professional burnout (PB) relation, but only few consider the role of ethical conflicts (ECs) in this context. The aim of this study was to characterize ECs' frequency and level of burden with them among nurses and to establish the relations between ECs' frequency, burden and PB. One hundred nurses participated in this study. ECs' frequency and burden were tested with an originally developed questionnaire. PB was examined with Maslach Burnout Inventory. Most frequent ECs concerned a nurse-patient (...) relationship. PB was positively related to ECs' frequency (r = .54; p = .001) and burden (r = .22; p = .03). Frequency of specific conflict did not imply burden with it and vice versa. ECs' frequency seems more important for PB than a level of burden with them. The most frequent and the most burdening conflicts may lead to development of PB but the less frequent and less burdening ones are also dangerous. (shrink)