To understand the perception of the quality of leadership relationships and the organizational commitment of nurses, and to analyze the influence of this relationship quality. Cross-sectional and correlational study, with a quantitative approach, using a non-probability convenience sampling with 408 nurses. The data were collected through questionnaires at Central Hospital in Lisbon, between January and March 2013. The statistical analysis of the data was carried out using IBM® SPSS® Statistics 19 software. Three hundred forty-two questionnaires were considered valid. The quality of the leadership relationship was satisfactory, and the nurses were poorly committed to the organization. The quality of the leadership relationship was statistically correlated with organizational commitment: there was found a moderate association to affective commitment (rs=0.42, p<0.05), a low association with the normative commitment (rs=0.37, p<0.05), and a very low association with the calculative commitment (rs=0.14, p<0.05). Leadership exerts influence on organizational commitment. An opportunity to improve the quality of the leadership relationship between nurses and their leaders was found, with the consequent possibility of developing organizational commitment.