The aim of this paper is to study the fluctuation of trust in a context of interaction between a board and a governed organization in the public sector. This paper is a response to the recent call on qualitative studies for understanding the complexity of interaction between boards and their governed organization and calls for adopting trust in this setting for understanding board efficiency and organizational performance. Based on empirical findings, we introduce and advance the fluctuation of trust in the public sector literature. This paper shows that trust is a complex and multidimensional concept. The types of trust discussed in this paper are cognitive, affective, contractual, competence and goodwill trust. The paper adds knowledge on how trust fluctuates and changes facets in the interaction process between a governing board and a governed organization. The multidimensionality of trust and its fluctuation effects captures the complexity in the interaction process and shows the importance of developing different types of trust for the benefit of organizational performance. We believe that trust fluctuation has the potential to advance our knowledge on the strength of different types of trust at different occasions in the interaction process.