In this work we analyse the evolution of organic agriculture in Europe from the point of view of Innovations Diffusion Theory in order to understand the characteristics of the process, and the factors that have determined its course in the past. From the corresponding diffusion models for data concerning the spread of organic farming in the fifteen countries belonging to the EU from 1985 to 2002, we conclude that the diffusion advance of organic cultivation has been driven by imitation. Furthermore, there is evidence that the characteristics of the diffusion process in each country depend on certain economic characteristics related with the purchasing power of its population, on the influence and experience of neighbouring countries that have adopted before and the moment at which any innovation is introduced.