This paper aimed to analyze the effect of transformational leadership on organizational efficiency of public limited companies in Bangkok. Data were collected from 310 participants who were administrators and employees working in fivepublic limited companies in Bangkok and suburban areas. The research questionnaire was used as an instrument to collect data. Descriptive statistics consisting of percentage, mean and standard deviation, and inferential statistics consisting of Pearson Correlation, and Multiple Regression Analysis were used to analyze the collected data. The research results showed that transformational leadership of public limited companies in Bangkok, in total, was perceived at high level. In particular, inspirational motivation had the highest mean value, followed by idealized influence, intellectual stimulation, and individualized consideration respectively. Organizational efficiency of public limited companies in Bangkok, in total, was perceived at high level. In particular, cost had the highest mean value, followed by quality, quantity and time respectively. Transformational leadership was positively related to organizational efficiency of public limited companies in Bangkok, which the highest correlation was a relationship between intellectual stimulation and organizational efficiency. Transformational leadership has an effect on organizational efficiency of public limited companies in Bangkok. In particular, intellectual stimulation had the highest effect on organizational efficiency of public limited companies in Bangkok, followed by idealized influence, inspirational motivation, and idealized consideration. The recommendations from this study were that the characteristics of transformational leadership are very much important and should be improved and cultivated in order to guide, motivate and inspire employees to work for the success and growth of the organization.