In the Ethiopian highlands, land degradation resulting from soil erosion and nutrient depletion is a serious environmental and socio-economic problem. Although soil and water conservation techniques have extensively been introduced over the past decades, sustained use of the measures was not as expected. Based on data obtained from 147 farming households, this paper examines the determinants of farmers' adoption and continued use of introduced stone terraces in an Ethiopian highland watershed. A sequential decision-making model using the bivariate probit approach was employed to analyze the data. The results show that the factors influencing adoption and continued use of the stone terraces are different. Adoption is influenced by farmers' age, farm size, perceptions on technology profitability, slope, livestock size and soil fertility, while the decision to continue using the practice is influenced by actual technology profitability, slope, soil fertility, family size, farm size and participation in off-farm work. Perceptions of erosion problem, land tenure security and extension contacts show no significant influence. Further, the results indicate the importance of household/farm and plot level factors in farmers' conservation decision. It is therefore concluded that 1) analysis of the determinants of adoption per se may not provide a full understanding of the range of factors influencing farmers' decision of sustained investments and 2) conservation interventions should focus not only on the biophysical performance of the measures but also on economic benefits that can be obtained at reasonable discount rates to the farmers in order to enhance sustained use of the measures.