Introduction: Violence and aggression of patients towards nurses is encountered in nursing practice in all clinical disciplines. Aggression is conditioned by the multifactorial influence of the environment, the personality of the patient and the nurse. Compared to other health care professions, nurses are exposed to aggressive behaviour much more often. Objective: The objective of the research was to determine whether nurses in the Slovak Republic (SR) are exposed to aggressive patient behaviour and which determinants most often condition aggressive patient behaviour. Methods: A self-designed questionnaire with a high internal consistency Cronbach alpha coefficient (0.870) was used. The sample consisted of 439 nurses working in hospitals in nursing units. We used k proportions comparison test using Marascuilo procedure at the significance level p < 0.0001. Results: 99.32% of nurses have experienced aggressive patient behaviour in all nursing units (the degree of experience is significant 0.4897 > 0.0813). Verbal aggression is statistically significantly higher than all other types of aggression (comparison test of two proportions; z = 13.9718; z krit = 2.3263; p = 1.158.10 -44 ≈ 0). 87.70% of nurses are exposed to physical aggression (p = 7.316.10 -111 ≈ 0). Conclusions: Nurses are the target of verbal and physical aggressive behaviour from patients. The most common determinants of patients' aggressive behaviour are abuse, pain, loss of self-sufficiency, the disease itself, and lack of information.