Background: Positive work environment help nurses to enhance their professional knowledge and competencies that in turn resulting in improvement of nurses' professional identity. Aim: Assessing the relation between work environment and professional identity among staff nurses in national and international hospitals. Design: A descriptive comparative study design was used for conducting current study. Setting: This study was conducted at Beni-Suef university hospital as an example of national hospitals and Saudi-German hospital as an example of international hospitals. Sample: A simple random sample of 460 nurses was used. Tools: Two data collection tools were used namely; a) Self-administered work environment questionnaire and b) The MacLeod Clark Professional Identity Scale. Results: Mean score of professional identity and work environment at Saudi German hospital (36.17 &135.79) is significantly higher than the mean score at Beni-Suef University hospital (31.23 &121.41) with p-value >0. 001. Conclusion: The work environment had a positive effect on nurses' professional identity at Beni-Suef University Hospital and Saudi-German Hospital. Moreover, work environment identified as a positive predictor of nurses' professional identity. Recommendations: Conduct workshops about how to create a positive work environment to enhance nurses' professional identity and engage nurses in decision-making especially regarding aspects that affect their practice as structure, system and instructions in health care organizations.