Introduction: In multicultural societies, nurses, like the rest of the population, carry prejudices toward the immigrant population. These biases determine their practice and the treatment of these patients, leading to inequalities in healthcare. Aim of the present study is to investigate the discriminatory behaviors of the nursing staff toward people of different ethnic origins as well as the factors that affect and are related to these behaviors. Material and Methods: A cross-sectional study design was applied in this study. Data were collected with a two-part self-reported questionnaire, the first part contained social, professional, and demographic information, and the second part was a validated instrument that measures nursing staff’s attitudes and views against discrimination. Data were analyzed with SPSS v.22. Results: From the total of 2034 nurses and nursing assistants, 85.4% were female, 32.8% 40–49 years old, and 99% of them were of Greek nationality. Age, gender, educational and marital status among other factors found to be associated with nurses’ attitudes and beliefs toward discrimination. Conclusion: Various social, professional, and demographic factors are associated with nurses’ attitudes and discrimination beliefs. Attitudes of health professionals, especially nurses, toward people of different ethnic origins, as well as the predictors of these attitudes of these factors should be assessed because they can contribute to the quality of the provided nursing care.