Introduction: In-service training of nurses plays an indispensablerole in improving the quality of inpatient care. Need to enhancethe effectiveness of in-service training of nurses is an inevitablerequirement. This study attempted to design a new optimal modelfor in-service training of nurses.Methods: This qualitative study was conducted in two stagesduring 2015-2016. In the first stage, the Grounded Theory wasadopted to explore the process of training 35 participating nurses.The sampling was initially purposeful and then theoretically basedon emerging concept. Data were collected through interview,observation and field notes. Moreover, the data were analyzedthrough Corbin-Strauss method and the data were coded throughMAXQDA-10. In the second stage, the findings were employedthrough Walker and Avant’s strategy for theory construction so asto design an optimal model for in-service training of nursing staff.Results: In the first stage, there were five major themes includingunsuccessful mandatory education, empowering education,organizational challenges of education, poor educationalmanagement, and educational-occupational resiliency.Empowering education was the core variable derived from theresearch, based on which a grounded theory was proposed. Thenew empowering education model was composed of self-directedlearning and practical learning. There are several strategiesto achieve empowering education, including the fostering ofsearching skills, clinical performance monitoring, motivationalfactors, participation in the design and implementation, andproblem-solving approach.Conclusion: Empowering education is a new model for in-servicetraining of nurses, which matches the training programs withandragogical needs and desirability of learning among the staff.Owing to its practical nature, the empowering education canfacilitate occupational tasks and achieving greater mastery ofprofessional skills among the nurses.Keywords: Grounded theory; Model; Nurse; Training