Background: Nurse practitioners (NPs) were first qualified in Taiwan in May 2007. The effectiveness of NP-related courses and training in enhancing nurse practitioner proficiency requires further investigation.Purpose: This study used Kirkpatrick's four levels of evaluation as its research framework and analyzed the influence of various NP demographic variables on NP training program effectiveness. This study also explored relationships among course satisfaction, individual proficiency improvements, and practical applications.Method: This study used a questionnaire to investigate subjects. Those recruited included nurse practitioners and senior nurses who had completed a nurse practitioners training program held by Department of Health-approved hospitals and had clinical care experience. A total of 250 questionnaires were distributed and 196 valid questionnaires were retrieved, giving a response rate of 78%.Results: All subjects held positive attitudes toward the effectiveness of their NP training program. In terms of course satisfaction, the questionnaire item "training courses can provide the latest concepts and knowledge" and "arrangement of training course schedules" earned the highest and lowest scores, respectively. In terms of personal proficiency improvement, "handling and implementation abilities" and "ethical decision-making abilities" earned the highest and lowest scores, respectively. In terms of practical application, "enable the implementation of physical examinations to fully evaluate patient health" and "enable the implementation of continuing care (including home care referrals, medical device leases, and physician-initiated visits)" earned the highest and lowest scores, respectively. Results further found that gender, age, average monthly income, marital status, education level, professional background, seniority, training institutions, and number of training years, respectively, had no significant impact on training effectiveness. Overall, results showed course satisfaction, individual proficiency improvements, and practical applications to be positively correlated.Conclusion: Research results can serve as a reference for planning nurse practitioners training programs in the future.