A total of ninety random samples of imported frozen fish represented by Mackerel, Herring and Saurus (30 of each) from
two different countries namely A and B (15 samples of each) were collected from different fish markets in Menoufiya
governorate. Each sample was weighed about 150 g and stored at -18oC. The collected samples were packed separately
in sterile polyethylene bag and transferred directly to the laboratory with minimum delay for determination of their toxic
residues. The obtained results recorded that the occurrence of histamine in both country (A) and in country (B) were
100% in the Mackerel, Herring and Saurus samples. The mean value of histamine in the country (A) samples were 38.14
± 2.93, 31.67 ± 2.15 and 19.05 ± 1.68 mg/kg in the Mackerel, Herring and Saurus, respectively. The average concentration
of histamine in country (B) samples were 33.96 ± 2.45, 24.51 ± 1.72 and 12.83 ± 1.19 mg/kg in the Mackerel, Herring
and Saurus, respectively. It could be inferred that regarding the products contamination, the highest histamine
contamination was in mackerel followed by herring then saurus. Regarding the locality, country (A) represented the
highest contamination of histamine followed by country (B)