Background: Nursing professional practice model creates a work environment for nurses that supports commitment to nurture and care and increases engagement to work. Work engagement is the strength of the mental and emotional connection nurses feel toward the work they do, team, and organization. Aim of the study: To assess the effectiveness of implementing nursing professional practice model on nurses' work engagement. Study design: A quasi-experimental research design was utilized. Setting: The study was conducted at critical care units at Benha University Hospital. Study subjects: Representative random sample of 170 nurses working in the above-mentioned setting. Tools of data collection: Three tools were employed; Tool Ι) Professional Practice Model Knowledge Structured Questionnaire, Tool ΙΙ) Professional Practice Model self-report Questionnaire, Tool ΙΙΙ) Work Engagement Scale. Results: The majority (92.9, 89.4% %) of nurses had adequate knowledge about nursing professional practice model at immediate post and follow up phases compared with preprogram phase. As well as the majority (98.2 %, 96.5 %) had satisfactory practice level at immediate post and follow up compared with pre-program phase. Additionally, 29.4% of nurses had low work engagement level at pre-program phase, which improved to 88.8%, 88.2% at immediate post and follow up phases. Conclusion: There was a positive correlation between nurses' total knowledge, practice and work engagement immediately post and follow up (after three months) of the program phases compared with pre-program phase. Recommendations: In-service training and education programs must be a continuous process for refreshing and increasing nurses' knowledge and practices about nursing professional practice model.