System of Rice Intensification (SRI) is one of the few innovations developed by the farmers that have resulted in greater level of interest and enthusiasm not only among the farmers but also among scientists. SRI was diffused first to Tamil Nadu State in India during the year 1999, followed by Andhra Pradesh. However, there is a need to study how SRI was diffused and adopted across the States of Tamil Nadu and Andhra Pradesh. The initial diffusion of SRI was mainly through literature. In Tamil Nadu, out of 31 districts, in 19 districts SRI has been introduced. At present out of 23 districts in Andhra Pradesh State, SRI has been introduced in 22 districts. The study revealed that farmers’ awareness of SRI happened during 2004-05. The gap between initial awareness and actual adoption ranged from one to twelve months. The delay in adoption was mainly due to labour and technical constraints. Mass media were the major sources of awareness for the farmers, while State Department of Agriculture and State Agricultural Universities were the major sources that provided subsequent knowledge and training. At present, the rate of adoption of SRI practices is at take-off stage. The important attributes which aroused the interest of farmers to gain more knowledge about SRI were high grain and straw yield, lower seed rate, less water requirement and less cost of cultivation. Few farmers discontinued (which is more of disenchantment discontinuance) due to more of labour and institutional constraints and less of technical reasons. Important reasons for non-adoption of SRI practices were risk involved in adopting new practices, shortage of agricultural labour and psychological fear of loss

Keyword: SRI; Diffusion; Adoption;