Objectives The overall aim of this systematic review was to identify the best available evidence on the relationship between the knowledge, competencies and behaviours of nurses exhibiting professional practice in their workplace; and the development of a healthy work environment. Search strategy The search strategy sought to find both published and unpublished studies written in the English language. An initial limited search of MEDLINE and CINAHL databases was undertaken to identify optimal search terms. A second extensive search using all identified key words and index terms was then undertaken. Methodological quality Two independent reviewers assessed the methodological quality of retrieved papers using the corresponding checklist from the System for the Unified Management, Assessment and Review of Information (SUMARI) package. Results Of the 4238 papers found in the search: 219 were selected for full paper retrieval; 19 of these papers were unable to be located; 200 full papers were assessed for methodological quality; 181 studies were excluded; and 19 were included in the review. Of these 19, four quantitative studies evaluated a professional nursing practice model and its impact on a variety of outcomes; five descriptive studies examined elements of nurses' professional practice and the impact these elements had on specified outcomes; and 10 qualitative papers examined varying behaviours, competencies and knowledge levels of nurses. Various methods were used, such as focus groups and open-ended interviews. Overall, the evidence suggests that professional practice has a positive impact on the work environment in terms of nurses' role satisfaction and patient outcomes. The evidence is, however, equivocal in many areas and the impact of the professional practice of the nurse requires further investigation. Conclusion The results of the review suggest a number of recommendations for practice and research on creating a healthy work environment.