The conjugate unsteady heat transfer between a translating droplet and its surrounding fluid at moderate Reynolds number is numerically investigated. The energy equation is solved by the ADI finite difference method with fluid motions inside and outside the droplet simulated by a series-truncation spectral method. The range of Reynolds numbers investigated is between 0 and 50. The ratios of viscosity and thermal conductivity between a droplet and its ambient flow range from 0 to 107 and 0.01 to 3, respectively. It was found that by increasing the Reynolds number, the predicted rate of heat transfer is significantly increased for fluid spheres as a result of increased fluid motions both inside and outside the droplet. On the other hand, the transfer rate for a solid sphere is much less sensitive to the Reynolds number than are the fluid spheres. For a gas bubble, any increase in the Reynolds number only increases the amplitude and frequency of the fluctuations in the Nusselt number and the steady-state Nusselt number is nearly independent of the Reynolds number.