The purpose of this study is to determine the relationship between transformational leadership of government secondary school principals and teachers' job satisfaction. A random sample of 320 teachers responded to a three-part instrument (the transformational leadership questionnaire, the teachers' job satisfaction questionnaire and a demographic section). Means, standard deviations, Pearson correlations and stepwise regression analysis were used to analyse the data. The findings indicated that a moderate, positive and significant relationship exists between transformational leadership (overall) and overall teachers' job satisfaction. Furthermore, the relationship between each component of transformational leadership and teachers' job satisfaction was found to be moderate, positive and significant. Finally, it is suggested that principals of government secondary schools in Ethiopia should pay more attention to developing efficient teamwork and the expression of warm concern and trust to co-workers through transformational leadership behaviours.