This research aims to determine the degree of knowledge needed by the agricultural extension agents researching the biological control of some diseases and pests of the potato crop in some governorates of Egypt. As well as determining the differences between the agricultural extension agents in the studied governorates concerning the degree of their knowledge needed for the biological control of some diseases and pests of the potato crop. Moreover, to determine the relationship between the total degree of knowledge needed by agricultural extension agents on the biological control of potato diseases and pests and each of the following independent variables: age, educational qualification, specialization, work period in the Ministry of Agriculture, work period in agricultural extension, training courses, and information sources. Moreover, to identify the sources of the respondents' information related to the biological control of some diseases and pests of the potato crop. Moreover, identify the problems related to the control of diseases and pests of the potato crop. Finally, identifying the most critical topics suggested by the respondents to be included in the training program on biological control of diseases and pests of the potato crop.