The purpose of this paper is to analyze interpersonal relationships of accounting employees affecting the effectiveness of firms’ performance. For this purpose, a structural equation model was adopted from Kang et al. (2004) and was tested. A questionnary was distributed to 187 companies’ accounting departments from Blacksea region of Turkiye which are choosen with arbitrary sampling method from the lists of related region’s Chambers of Commerce and Industry. We find that, although no significant relation between balanced power and confidence, there are significant relationships between conflict and confidence, shared values and confidence, conflict and collaboration, shared values and collaboration, balanced power and collaboration, communication and collaboration. Overall our findings indicate that confidence and collaboration among the accounting department employees have direct influence on the firm performance