Purpose: The paper reports the importance of positive employee attitudes such as work engagement and job satisfaction for project success and business excellence. It is based on two different research projects. The first one, conducted in 2007, entitled “Self-assessment in quality management systems of companies”, was concerned with the engagement of Polish enterprises in initiatives aiming at business excellence. The second study called “Project management efficiency in the enterprises operating in Poland”, completed in July 2008, dealt with the identification of project success factors. Methodology: EFQM Excellence Model indicators were used as the evaluation criteria for the first study. A structured questionnaire built upon them was distributed among the most active companies in the Polish economy. The research sample PL2007 numbered 230 companies was collected as a result of the study. The second research resulted in the sample PL2008 mostly formed on the basis of the member list of the Polish Project Management Association. In total, 70 respondents filled out the questionnaire which made it possible to identify the project success factors. Findings: The results coming from the 2007 study indicate that the key factors influencing examined firms’ performance are related to people and their satisfaction. At the same time they are the most critical factors for business excellence improvement. The results of the research project carried out in 2008 show that among a few dozen of tested factors which are conducive to successful realization of projects, the most significant ones are again those referring to people, especially to their engagement. Originality/value: The paper combines the research results generated in two different studies conducted in companies operating in Poland, the first one focused on business excellence indicators and the second one concentrated on project success factors. Presented data make it possible to indicate how strongly performance on both the operational (project) level and the strategic (business) level is influenced by employee attitudes.