This paper examines the relationship between interdepartmental dynamics and market orientation of service firms in Tanzania. The study used a sample of 177 hotels, insurance agents, tour operators and travel agents from seven regions in Tanzania. Complex random sampling was used to select 177 firms. It involved purposive sampling to ensure inclusion in the sample of hotels, insurance agents, tour operators and travel agents. Simple random sampling was used to pick final firms that constituted the sample. Analysis of Moment Structures was used to estimate the structural equation model using Maximum Likelihood Method. The study used MARKOR to measure market orientation of service firms in Tanzania while interdepartmental dynamics were measured by a scale developed and tested by Jaworki and Kohli (1993). Findings indicated that interdepartmental dynamics (defined as interdepartmental conflict and interdepartmental connectedness) relate to market orientation of service firms in Tanzania. Specifically, results showed that interdepartmental conflict negatively influences on intelligence dissemination and organizational responsiveness components of market orientation but has no influence on intelligence generation component. Furthermore, findings from the study showed that interdepartmental connectedness influences positively on intelligence dissemination and organizational responsiveness components of market orientation but has no influence on intelligence generation. On the basis of findings, the paper recommends to organizations to manage interdepartmental conflicts at the earliest possible stage and nurture teamwork among departments for them to implement market orientation. Empirical findings from the study contribute to theory of antecedents to market orientation.UDSM