Introduction: Smoking is a leading public health problem and one of the main causes of death in Croatia. There are a number of evidence-based interventions for smoking cessation, including nursing interventions which nurses may implement during their work with patients or in the community. Objectives: The aim of this study was to examine which interventions for smoking cessation are carried out by nurses and to examine their knowledge and attitudes about these interventions. Methods: The research was conducted in eight clinics of the Sestre milosrdnice University Hospital Centre in Zagreb, Croatia, from April to June 2022 on a random sample of nurses. The nurses filled out the questionnaire at their workplace. The data were collected using an anonymous questionnaire, which in the first part contains questions about the sociodemographic data of the respondents. In the next part of the questionnaire, there are questions about the frequency of implementation of 5P interventions for smoking cessation during their work (5P: ask, advise, assess, help, monitor) using "The 19-item Helping Smokers Quit" questionnaire. Then, their attitudes and knowledge about smoking cessation skills were examined. The smoking status of the nurses was also examined (never smoked, former smokers, smokers). Results: Out of 340 distributed questionnaires, 258 nurses filled out the questionnaire (response rate was 76%). Slightly less than half of the respondents (43%) responded that they always ask the patient in their work whether they use tobacco products, thus opening up the possibility of using interventions to stop smoking. However, only 7 (2.7%) respondents indicated that they always help the patient to stop smoking. Almost all of them (98%) did not attend any training in the past two years that would have given them the knowledge and skills to help patients quit smoking, and 82% of them never had such training during their education. Almost half of the respondents (44%) were smokers. Differences were observed in the attitudes of nurses who smoke versus those who do not smoke. Nurses who smoke compared to nonsmokers believe that their behavior does not influence the patient's perception of smoking, i.e., that they should not be a role model for patients by not smoking (P = <0.001). Furthermore, nurses who smoke compared to nonsmokers do not question patients as much about the reasons for not being able to quit smoking (P= 0.010). Conclusion: Despite the fact that smoking cessation interventions delivered by nurses are proven to be effective, such interventions are insufficiently used by a small number of nurses. A small number of nurses have undergone training to acquire the knowledge and skills to help smokers quit smoking. There is a large number of smokers among nurses, which can affect their attitudes and the implementation of interventions for smoking cessation in the workplace.