This paper describes a study that focused on long-term web-supported learning diffusion among lecturers at Tel Aviv University (TAU), from an organizational point of view. The theoretical models we used to examine this process are Rogers' model for "Diffusion of Innovation" (1995) and Bass's "Diffusion Model" (1969). The study was conducted between the academic years 2000/01 and 2007/08. At that time TAU implemented a project aimed to integrate knowledge technologies in academic instruction. The main results show that the diffusion process among lecturers using web-based instruction was rapid and reached over 77% of the total lecturer population. However, differences in diffusion among lecturers were found in terms of academic units. The diffusion process found behaves similarly to Rogers' Diffusion of Innovation theory and Bass's diffusion model. (Contains 1 table and 7 figures.)