Trust in the leader, the belief that one can rely on the leader’s actions and words and that the leader has good intentions toward oneself (Dirks 2000), is related to a variety of positive outcomes. Trust in the leader mediates the relationships between transformational leadership and job satisfaction (Braun et al. 2013), followers’ helping behavior toward co-workers (Zhu and Akhtar 2014a), employees’ psychological well-being (Kelloway et al. 2012), and perceived work stress and stress symptoms (Liu, Siu, and Shi 2010). Two issues concerning the relationships between transformational leadership, trust in the leader and positive outcomes, however, remain unexplored. The first is the mechanism by which transformational leadership is related to trust in the leader; the second is the influence of trust in the leader on employees’ turnover intention. We believe that followers trust not only their leaders’ actions but also their words, particularly truthful and polite words; we therefore expect leaders’ right speech to mediate the relationship between transformational leadership and trust in the leader. Right speech (samma vaca) is one of the items of the Buddhist Noble Eightfold Path, which also contains right view, right resolve, right conduct, right livelihood, right effort, right mindfulness, and right Samadhi (Maggavibhanga, Abhidhammapitaka, 78/258/5691 ). We also believe that, in addition to positive outcomes such as job satisfaction and psychological well-being, trust in the leader influences to reduce employees’ turnover intention. We therefore expect transformational leadership, right speech, trust in the leader, and turnover intention to be related as shown in the model (Figure 1). Thus, right speech and trust in the leader will mediate the relationship between transformational leadership and turnover intention. To test our belief, we conducted a study among 164 participants who were employees of commercial banks in Thailand. Thailand is a country in Southeast Asia with a population of 65.9 million; Bangkok, its capital, has a population of 8.3 million (National Statistical Office 2015). As of the third quarter of 2016, there were 19 commercial banks in Thailand, with 150,180 employees (Bank of Thailand 2016a); a total of 2,155 of the 7,033 branches were in Bangkok (Bank of Thailand 2016b). Despite their large number, there does not seem to be any study of Thai commercial bank employees. Our study is important in that it will develop a scale to assess Buddhist right speech and provides support for our belief that right speech will mediate the relationship between transformational leadership and trust in the leader. Right conduct has been defined as observance of the Buddhist five precepts, which include a pledge against idle talk (Ariyabuddhiphongs 2007); right speech has been defined as including not lying, speaking maliciously of others, using bad words, and engaging in idle talk (Brahmajalasutta, Atthakatha, D, 11/-/192-199). Right speech will be defined operationally in this study. The Right Speech Scale thus developed will be used to assess leaders’ verbal interaction with their followers.