1   Sixty random samples of some fresh water fish species: Tilapia nilotica (Bolti), Mugil cephalus (Bori), Clarias lazera (Karmout) and Cyprinus carpiol (Carp) (15 of each) were collected from fish markets of Damanhour city for detection of lead and cadmium levels in their muscular tissues using Perkin-Elmer atomic absorption spectrophotometer. The reported results showed that the mean values of lead in the examined samples of the fore-mentioned fish species were 0.360±0.090, 0.720±0.550, 1.315±0.975 and 0.568±0.064 ppm, wet weight with an incidence of 13.3% to each of Bolti, Bori and Karmout, 33.3% for Carp. While that of the cadmium were 0.020±0.005, 0.019±0.006, 0.016±0.003 and 0.014±0.003 ppm wet weight with incidences of 46.7% 20.0%, 66.7% and 40.0%, respectively. The percentages of the examined samples of Bolti, Bori, Karmout and Carp for lead levels which not exceed the permissible limit (0.1 ppm) according to the Egyptian Organization for Standarization and Quality Control "EOSQC" (1993) were 86.7% for each of Bolti, Bori and Karmout, 66.7% for Carp and the values of examined samples for cadmium level not exceed the permissible limit (0.1 ppm) according to
"EOSQC" (1993). The puplic health significance and the hazardous toxic effects of these heavy metals were discussed. In addition, recommendations regarding the consumption of fish from the health authorities should be taken for protection of fish consumers. The governmental role is to improve the enforcement of the safety, health and environmental laws.