This study uses a panel data set of 25 years over 280 districts in rural India and applies a geographic information systems (GIS) program to investigate the regional neighborhood effect on the rate of diffusion of new technologies. The results show that in the technology diffusion process, the early successful adopters have a larger effect on neighboring adopters than do the early unsuccessful adopters. Hence, use of the aggregate or the simple average of adoption rate among neighborhoods as a proxy for the neighborhood effect, a common practice in the learning literature, may be inappropriate. We also find that education and irrigation play important roles in facilitating technology diffusion.