Seventy-five random samples of marketed fish (25 of each fresh Tilapia nilotica, fresh Mugil cephalus and frozen Mackerel) were collected from different fish marketes in Damanhour city for microbiological examination. The results revealed that the mean values of total counts of aerobic mesophilic bacteria, psychrotrophic bacteria, Enterobacteriaceae, Coliforms, Staph. aureus, Pseudomonas, Aeromonas, as well as Moulds and Yeasts of examined fresh samples of Tilapia nilotica were 2 x 105 ± 1 x 104, 2 x 104 ± 9 x 103, 2 x 104 ± 7 x 103, 3 x 102 ± 2 x 102, 4 x 104 ± 2 x 104, 1 x 104 ± 4 x 103, 7 x 103 ± 2 x 103, 1 x 103 ± 4 x 102 and 1 x 103 ± 4 x 102 respectively. While that of examined fresh samples of Mugil cephalus were 1 x 104 ± 1 x 103, 1 x 104 ± 1 x 103, 7 x 103 ± 1 x 103, 2 x 102 ± 2 x 102, 6 x 103 ± 2 x 103, 6 x 102 ± 2 x 102, 2 x 104 ± 2 x 104, 2 x 102 ± 5 x 10 and 6 x 102 ± 3 x 102 respectively, and that of examined frozen Mackerel fish samples were 4 x 103 ± 1 x 103, 4 x 103 ± 2 x 103, 3 x 102 ± 9 x 10, 3 x 10 ± 1 x 10, 4 x 103 ± 9 x 102, 7 x 103 ± 5 x 103, 4 x 103 ± 4 x 103, 1 x 103 ± 1 x 103 and 5 x 103 ± 2 x 103 respectively. The results of most of examined fish samples were in compliance with the Egyptian and the international permissible standard limits. The recommended measures for improving the microbial quality of the marketed fish were discussed to become more safety for the consumers.