Biogenic amines are formed in some foods, especially fish and fish products as a result of the process of decarboxylation of free amino acids in food. The histamine (scombroid) poisoning arises from ingestion foods containing relatively high levels of histamine and other amines that act as histamine potentiators. Therefore, this study aims to explore the level of contamination by biogenic amines in fish and fish products in shore of Thuel -Saudi Arabia. One hundred and twenty of different fish samples were collected from Thuel shore markets. The biogenic amines histamine, cadaverine, putrescine and tyramine were determined in all samples and also in selected fish samples held iced for 0, 24 and 48 h. The effect of the commercial frying process on biogenic amines level was also tested using two different types of fish. Quantitative thin layer chromatography (TLC) analysis was used in biogenic amines determination. There are significant differences between the tested samples and the highest mean (mg/100 g) of putrescine. Cadaverine, histamine and tyramine were in loat fish (6.57), Baiad (3.348), Hareed (4.82) and Baiad (1.38), respectively. Significant increases in the level of biogenic amines were observed in fish held iced at 0, 24, and 48 h. A significant increase of histamine level was noticed in selected fish after commercial frying process.