In Ethiopia, Cereal production and marketing are the means of livelihood for millions of small holder households and it constitutes the single largest sub-sector in economy. Out of the total grain crop area, 79.69% (8.7 million hectares) was covered by cereals. Teff and wheat covered up 23.42% (about 2.6 million hectares) and 13.01% (1.4 million hectares) of grain crops area respectively. Agricultural production and productivity is very low and the growth inagricultural output has barely kept pace with human population growth. Supply of agricultural crop in the study area is subjected to seasonal variation where surplus supply at harvest is the main feature. There is lack of sufficient studies which tries to look into the determinants of their supply in Dendi district. This study helps in the understanding of determinants of teff and wheat supply in the district. For the purpose of this study, Dendi district was selected purposively. In the second stage, out of the 48 rural PAs of Dendi district , 4 PAs each for teff and wheat were selected randomly by using simple random sampling technique. From the available 23 Teff producing PAs, three were selected randomly. From these 23PAs, 80 HHs of Teff producers and 80 HHs of wheat producers were selected randomly. Data were collected: Two types of analysis, namely descriptive and econometric analysis are used for analyzing the data collected from farmers and traders in the study area. Eleven explanatory variables were hypothesized to determine the household level marketable supply of Teff and Wheat. Among these variables, only five variables namely (quantity produced, age and market access, experience and price) were found to be significant while (education, quantity produced and extension access) were found significant for Wheat. The quantity of Teff and Wheat produced at the farm level affected marketable supply of Teff and Wheat positively and significantly. Introduction of improved varieties, application of chemical fertilizers, using of modern technologies, controlling disease and pest practices should be promoted to increase production. Education has improved the producing household’s ability to acquire new idea in relation to market information and improved production, which in turn enhanced productivity and thereby increased marketable supply of Teff and Wheat. Therefore, there is a great need to make information available to farmers at the right time.