Growth of Escherichia coli, Proteus spp, P.aeruginosa, Staphylococcus epidermidis, Staphylococcus aureus and Enterococcus faecalis were studied in the presence of 20 to 320 mg/ml Na-saccharin. Spectrophotometric methods were used as a measure for growth. At low concentrations Na-saccharin had an inhibitory effect on the growth of E.coli and Proteus spp but had no effect on the growth of P.aeruginosa, S.epidermidis, S.aureus and E.faecalis. On the other hand, at higher concentrations Na saccharin inhibited the growth of all bacterial species including P.aeruginosa, S.epidermidis, S.aureus and E.faecalis.