The purpose of this study was to determine the mediating effects of the Basic Psychological Needs at Work, comprised of competence, autonomy and relatedness, on the relationship between the Dimensions of the Learning Organization and affective and normative organizational commitment in the United States nursing population. The study incorporated Marsick and Watkins (2003) Dimensions of the Learning Organization Questionnaire-Abbreviated, Meyer and Allen's (2004) Three Component Model of Employee Commitment Questionnaire-Abbreviated, and Ryan and Deci's (1998) Basic Psychological Needs Scale-Work. Participants were a purposeful sample of 870 registered nurses from seven, state-based professional nursing organizations located in the United States. Data analysis provided validity and reliability findings for all three instruments, two of which, the DLOQ-A and BPNS-W, had not previously been used exclusively with RNs in the United States. Regression analysis and SEM findings demonstrated that autonomy and relatedness partially mediated the relationship between the Dimensions of the Learning Organization and both affective and normative organizational commitment: competence was not a significant mediating variable. This study demonstrated that the dimensions of the learning organization met the need for autonomy and relatedness at work, which increased the affective and normative organizational commitment of nurses. This impacts healthcare organizations and HRD by providing validity and reliability for the DLOQ-A, BPNS-W and TCMQ-A for use with registered nurses in the U.S. and also provides a study design and findings that can be used to shape future research and learning organization implementation. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]