Some aquatic insects and invertebrates were used for monitoring the effect of bacteriological pollution upon water quality during two years (October, 2001- August, 2003) at six sampling sites situated at El-Zomor and El-Mariotya canals (branches from the River Nile), Giza Governorate, Egypt. Results obtained revealed that 5 species of bacteria (Escherichia coli, Klebsiella pneumonia, Enterococcus faecalis, Streptococcus faecium & Proteus mirabilis) were detected from water samples. K. pneumonia, S. faecium and P. mirabilis were not detected at IIIZ site and; S. faecium was not detected at IIZ sampling site. Meanwhile only two species (E. coli & E. faecalis) were detected in all El-Mariotya canal sampling sites. E. coli & E. faecalis showed high bacterial counts during summer months. The bacterial species isolated from aquatic insects belong to different orders mainly Diptera; Ephemeroptera and Odonata; however, there is no isolation of bacteria from aquatic invertebrate belonging to orders Cladocera & Cyclopoida. The 5 bacterial species that were detected in the water samples were isolated from the collected aquatic insects at IZ sampling site, while at IIZ sampling site 4 species (E. coli, K. pneumonia, E. faecalis & P. mirabilis) and only two species (E. coli & E. faecalis) at IIIZ sampling site. However, only 2 species of bacteria (E. coli & E. faecalis) were isolated from ElMariotya canal. It is clear that some aquatic stages of Diptera, Ephemeroptera and Odonata could be selected as bioindicator of water bacterial pollution.