Background Little is known regarding the factors that affect the team-based practice of nurse practitioners (NPs). Examining the relationships between these factors and team-based practice may provide important insights into the strength of the NP practice. Purpose This study was designed to examine the effects of practice autonomy and leadership style on the team-based practice of acute care NPs working in hospitals. Methods A cross-sectional, national survey design was conducted to examine the autonomy, leadership, and team-based practice of NPs. One thousand three hundred ninety-one NPs completed the questionnaire, which included demographic and practice variables, the Dempster Practice Behavior Scale, the Multifactor Leadership Questionnaire, and the NP-physician relations subscale of the Nurse Practitioner Primary Care Organizational Climate Questionnaire. The hierarchical linear model was used to differentiate between the NP-level and organization-level effects on team-based practice. Multiple regression was applied to explore the factors associated with team-based practice. Results The hierarchical linear model results identified no organization-level effect on team-based practice. Moreover, the results of the regression model found that NPs with greater autonomy in actualization, empowerment and readiness, and idealized influence leadership style enhanced the performance of the doctor of medicine-NP team-based practice. The final model explained 39% of the variance in doctor of medicine-NP team-based practice. Autonomy in actualization and empowerment were identified as the two most important predictors. Conclusions/Implications for Practice The practice autonomy and leadership style of NPs influence the efficiency of team-based practice in Taiwan. To improve the team-based practice of NPs, healthcare administrators must support the practice autonomy of NPs.