This research mainly aimed to identify the knowledge obstacles of fish breeders that limit the productivity of fish farms in Kafr El-Sheikh Governorate, and Kafr El-Sheikh Governorate was chosen as a region to conduct this research, as it occupies the first place at the level of the Republic in fish production, and includes ten administrative centers that practice fish farming. In six of them, Al-Hamoul Center was randomly selected from them to conduct this research, for a regular random sample of 150 respondents who were selected from the villages of Al-Amal and Al-Mamoura villages, and the most important results of the research were summarized as follows: The groups of obstacles that the research was exposed to came in the following order according to their relative importance to the respondents, the obstacles of lack of knowledge of methods of prevention and treatment of fish diseases came in the first order with a weighted degree of 2.67 degrees, and in the second order came the obstacles of lack of knowledge of the fish farming environment with a weighted degree of 2.65 As for the obstacles of lack of knowledge of the foundations of fish nutrition, they came in the third place, with a weighted degree of 2.48 degrees, and they came in the rankings. The fourth is the obstacles of lack of knowledge of incubating the pretext with a weighted degree of 2.15 degrees.