Importance of agricultural technology in enhancing the welfares of farmers can be realized when gain yield from technologies result in meaningful gain in nutritionally adequate food. Adoption and wider diffusion of improved teff varieties is playing vital role in improving household’s food security and there-by contributing to nutrition security in many parts of Ethiopia. However, the uses of improved teff varieties are constrained by various factors. This study, therefore, analyzed the probability and use intensity of improved teff varieties adoption and its impact on households’ food security. The data was collected from Simada woreda, Amhara Region in 2020. The survey consists of 256 sampled teff growers out of whom 138 were improved teff variety users and 118 were non-users. In this study a multi-stage stratified sampling technique was employed to select rural Kebeles and households. The study used cross-sectional data collected in 2020 production season from sample households. Descriptive statistical tools like mean, standard deviation, percentage, and frequency distribution were used to summarize the characteristics of the sampled households. Both logit and Tobit model were used to analyze factors affecting adoption probability and adoption intensity of improved teff varieties respectively and an endogenous switching probit model (ESPM) was used to analyze the impact of improved teff varieties on households’ food security. Educational level of the household head, land size, availability of neighbor adopter, off/non-farm income, participation in training, use of credit, membership of co-operatives and distance to nearest market were found as the factors of adoption and intensity of adoption. The Endogenous switching probit model result shows that, average treatment effect of adopters was 31.61 % higher in probability of food security as compared with the counterfactual case of non-adopters. The results suggest that promotion and adoption of improved teff varieties, by strengthening extension service, will contribute to improve the food security status of the farming households. Keywords: Adoption, Endogenous switching probit model, Ethiopia, Food security, improved teff Variety, Impact, Logit model, Tobit model.