The main objective of this study to know the knowledge level of extension workers in Asyut  governorate in the area of bio-fertilizers , to identify extension workers source of information about bio-fertilizers, and to determine the relationship between the knowledge level and some studied independent variables . 1- The search was carried out on the population of workers in Asyut district. Percentages, chi square, tschuprow test were used to analyze the data. Results showed that the knowledge level was high for one statement middle for tow, and low to others, that 22% only was the highly for the total. - That training meetings was the most important source for information about bio-fertilizers. - That age and training meetings were effected by 11% in knowledge level