Background. Moral distress resulting from frequent and intense exposures to morally challenging encounters with critically ill patients, their families and other healthcare professionals negatively impacts on the personal and professional wellbeing of critical care nurses. Objective. To determine the frequency, intensity and overall severity of moral distress among critical care nurses working in the critical care environment of a private hospital in the eThekwini district of KwaZulu-Natal Province, South Africa. Methods. A descriptive survey was conducted using a 21-item moral distress scale revised questionnaire. We assessed the influence of sociodemographic variables of the respondents on the moral distress composite scores. Results. The moral distress composite scores of the 74 critical care nurses who completed the questionnaires ranged from 0-303 out of a possible 336. The mean (standard deviation (SD)) composite moral distress score was 112.12 (73.21). Analysis of the relationship between sociodemographic variables and the moral distress composite scores revealed that female respondents experienced higher distress scores than males (p=0.013). There was an inverse relationship between composite scores and an increase in age (p=0.009) and years of service (p=0.022). Conclusion. The mean composite score of the critical care nurses was suggestive of moderate levels of moral distress. Counselling services and empowerment skills training are advocated to support critical care nurses to manage moral distress. Keywords. moral distress; critical care nurse; critical care unit.