Hospital nurses are not active in encouraging patients to give up smoking because of certain beliefs and attitudes. These beliefs and attitudes must be measured in order to change smoking cessation practices. The aim is to develop and validate a questionnaire on hospital nurses’ smoking cessation practices. Methodology: a methodological study was conducted to construct a questionnaire (n=118) according to the theory of planned behavior, to validate it by four experts, for reliability of instruments and validation of constructs (n=38; n=29; n=157). Results: an initial questionnaire on smoking cessation practices was created according to the beliefs of a convenience sample of 118 nurses. Validation of experts was conducted, and the questionnaire obtained an index of content validation (ICV) of 0.94. Subsequently, after two convenience samples (n=38; n=29) and a random sample (n=157), the questionnaire obtained reliability, measured by Cronbach’s alpha ranging from 0.697 and 0.931. Finally, moderately high correlations (0.406 to 0.569) were obtained between concepts. Conclusion: a reliable and valid questionnaire in French is available to measure smoking cessation practices.