This paper analyses the impact of technology characteristics on the rate and speed of adoption. In a case study of the Meru district in Kenya, 17 dairy technologies are analyzed with respect to the influence of relative complexity, relative risk and relative investment characteristics on adoption. Technology characteristics were measured by a scoring approach which involves assessments made by extension workers working in the study area. The study found that the past process of adoption and diffusion was significantly influenced by the characteristics mentioned above. Considering the speed to completed adoption, the influence of relative investment was smaller while relative complexity and relative risk showed significance. The strong influence of relative complexity and relative risk of the technologies on the adoption can be explained by the characteristics of farmers and the farming circumstances. Meru farmers are poorly educated and face shortage oflabor making them hesitant to adopt complex technologies. Moreover, the risk of production is high leading farmers to adopt new technologies that reduce risk relative to the traditional technologies. Knowing this, planners in research and extension should advise the development of risk-reducing technologies with a low complexity as compared to the technologies that should be replaced. © 1999 Elsevier Science B.V. All rights reserved.