A total of 300 fish samples were collected from Giza and Cairo shops, supermarkets and restaurants. these samples were 150 raw fish samples of Tilapia, Mackerel and Sardine (50 for each) and 150 ready to eat fish samples of fried Tilapia, grilled Mackerel and grilled Sardine (50 for each). samples were subjected to bacteriological examination for detection of aerobic spore forming bacteria. The obtained results indicated that, the infection rate with aerobic spore formers in raw Tilapia, Mackerel and Sardine were 60 %, 70 % and 100 %, respectively. While in fried Tilapia, grilled Mackerel and grilled Sardine were 30%, 14% and 20 %, respectively. The highest count of aerobic spore forming bacteria in raw fish samples found to be high in raw Sardine (7 x 103cfu/gm) while the lowest one in raw Tilapia, Mackerel and Sardine were (1 x 102 cfu /gm) for all. In ready to eat samples the highest count found in fried Tilapia samples (6 x 102 cfu/gm). Four serotypes of aerobic spore formers recovered from raw fish; B.cereus , B. subtilis, B. lanchiniformis and B. macerans while  in  ready to eat fish the same serotypes were found besides B. mycoides