Io is Jupiter's innermost Galilean satellite and the most volcanically active body in the Solar System. Its volcanism is driven by tidal heating generated by its interaction with Jupiter and maintained by other Galilean satellites. The tidal forces acting on Io also cause significant stresses on its interior. It is investigated if tensional stresses play a significant role in the formation of volcanic centers on Io. On a global scale, it is investigated if the locations of maximum tensile stress coincide with the locations of maximum volcanic activity. On a local scale, it is investigated if chains of Io's volcanoes follow the directions of the tensile stresses. The results on a global and local scale are shown to be consistent with the hypothesis that tensional stresses play a significant role in the formation of volcanic centers on Io. However, tensional stresses alone are insufficient for the formation of volcanic centers.