This paper presents an analytical study of oscillating flow in a capillary tube to determine the oscillatory flow effect on the heat transfer coefficient and find whether there exists an optimum condition for the maximum heat transfer coefficient. Based on a uniform heat flux boundary condition, analytical solutions of temperature distribution and Nusselt numbers are obtained for an oscillating laminar flow, which can be used to analyze the effects of flow type including thermal properties on the heat transfer performance. The result shows that the dimensionless oscillating frequency, omega*, amplitude, gamma, and Prandtl number, Pr, are primary factors affecting the heat transfer performance of an oscillating flow in a capillary tube, which can be used to determine an optimum condition of the maximum heat transfer coefficient. (C) 2013 Elsevier Ltd. All rights reserved.