The purpose of this dissertation was to: examine agent-based modeling (ABM), a new methodological tool, from a nursing philosophy standpoint; evaluate its disciplinary fit; and use the tool for creating and testing a model of nursing opinion leadership. First, in a philosophic analysis of ABM, recurrent themes concerning the use of ABM in multidisciplinary research were identified. These themes (heterogeneity, dynamics, adaptation, emergence, and the metaphorical use of the term "bridge" to describe ABM) were examined from various philosophical positions in nursing. The ABM themes were found to be compatible with multiple philosophic viewpoints within nursing. Further analysis, linking the recurrent themes with nursing metanarratives via exemplars from nursing systems research, revealed that ABM is a methodological tool that is congruent with nursing values. Next, a model of nursing opinion leadership, derived from two philosophic theories of belief formation was developed. The resulting model was then programmed as an ABM. Simulated data, obtained from model execution, depicted opinion leadership as a dynamic process that develops under conditions of uncertainty when credible individuals are available to act as opinion resources. Overall, this dissertation demonstrated the usefulness of ABM as a methodological tool for theory development in nursing.