Some 25 years after the introduction of the first geo-information technologies in public organizations, strategies to manage their diffusion are still inadequate. This is problematic in light of the new generation of geo-information technologies that has become available and aims to invest in these new information technologies in order to advance e-government. This study questions how strategies for diffusion of geo-information technologies in public planning organizations can be improved. It shows that classic top-down management often enhances informal diffusion activities that deviate from the formal diffusion strategy. A knowledge management approach, in which geo-information specialists and planners participate in the formation of diffusion policies, can enhance the quality of the formal strategy, thereby preventing deviation and informal diffusion activities. The authors recommend that public planning organizations use this knowledge to improve their diffusion strategies for geo-information technologies.