Organizations have started to recognize that a competitive advantage can be gained through human resources. As such, there has been considerable interest in the study of organizational commitment, primarily because of relationships between it and various measures of organizational efficiency and effectiveness. One of the critical antecedents of organizational commitment is leadership. The primary purpose of this study was to examine how much organizational commitment, in all three forms, was influenced by leadership. This study expanded the research on the relationship between normative and continuance commitment with transformational leadership. In addition, it used the previously untested combination of LPI and the Organizational Commitment Scales. Self-administered surveys were distributed to collect employee attitude and demographic data. A total of 129 surveys were distributed to two different organizational populations, a petroleum products redistribution and services company and a hedge-fund trading firm, both located in Houston, TX. The response rate for the total distributed was 69%. The internal consistency, reliability and scale statistics were calculated for the scales. Relationships between the three forms of organizational commitment and the five leadership practices were investigated using correlation analysis and linear regression. The three forms of organizational commitment and the demographic characteristics were tested using t-tests and analysis of variance (ANOVA). The results, conclusions, and limitations of this study are described in the final chapter as well as recommendations for future research. The overall conclusion of this research is that the five leadership practices has been observed to be correlated with both affective and normative commitment attitudes among the employees of the two organizations in this study when practiced by managers.