The Hittite city Sarissa was founded in the 16th century BC and has been systematically constructed. The city gates and the bigger public buildings were arranged at about 45° relative to the cardinal directions. However, one of the temples features a remarkable deviation from this general orientation. The following analysis shows that both, the general orientation of the public buildings and the deviation of one of the temples are related to astronomical observations, particularly to the course of the sun, and maybe also to some special points of the course of the Venus.