Wheat is the second most important crop in Kenya after maize and is becoming an important source of food both for humans and livestock. Despite increasing wheat production, only 50% of domestic consumption requirements are being met. While the National Plant Breeding Research Centre at the Kenya Agricultural Research Institute has released more than 100 wheat varieties since it began operations in 1927, adoption has been slow in spite of better performance of new varieties. This study examined factors that influence farmers’ adoption of new varieties in the Narok, Nakuru, and Uasin Gishu Districts that account for 80% of Kenya’s domestic wheat production. The study found that most farmers in these Districts neither knew nor grew new wheat varieties, reflecting lack of seed and knowledge of these new varieties. Wheat varieties were also often not adopted in agroecological zones for which they were targeted. This should be an issue of concern to wheat breeders since varieties are currently bred specifically for agroecological zones. The main sources of wheat seed (old and new) for both smallscale and largescale farmers were other farmers. The adoption of new wheat varieties was significantly higher among largescale farmers in the high potential zone in Uasin Gishu District than among smallscale farmers in the low potential zone in Nakuru and Narok Districts. The logit model showed that experience in wheat farming had a positive impact on adoption of new wheat varieties. These factors will need to be taken into account by researchers, extension specialists, and policy makers.14 pages