The study aims to identify the role of transformational leadership toward work performance through intrinsic motivation in pharmaceutical field by a survey of 220 pharmacists in Vietnam. The pharmaceutical industry in Vietnam is experiencing rapid growth, accompanied by the need for a change in leadership for managers. The transformational leadership creates a proactive, positive attitude, passion, interest or an increase in intrinsic motivation of employees, thereby affecting work performance. This study performed reliable verification by Cronbach’s Alpha coefficient, then the factors are analyzed by EFA before conducting multivariate regression analysis. The results showed that the transformational leadership style includes such factors as: idealized influence (attributed and behavior), inspirational motivation, intellectual stimulation, individualized consideration have a positive impact on intrinsic motivation and thereby positively affecting work performance. It confirms that employees will have a higher intrinsic motivation level when working under transformational leadership from their leaders. It makes employees work more efficiently. According to the research results, the pharmacist has an intrinsic motivation to work hard on tasks that contribute to the group overall goal of. That requires managers to have a task assignment strategy to connect the goals of the members together as well as of the members to the group.