This report deals with the study made of the treatment of 45 acute, subacute and chronic urinary infections in a department of general medicine. 43 of these were infections caused by a single species of bacteria and 3 were caused by more than one species. The sensitivity test of the isolated organisms (E. coli, Proteus, Serratia, Pseudomonas, Klebsiella and S.faecalis) showed 83.33% of the strains to be sensitive and 16.8% of the strains to be resistant. Nevertheless, this last group of strains, with the exception of one Pseudomonas, proved to be sensitive to the association of fosfomycin with a β-lactamin (carbenicillin, amoxycillin) or an aminoglycoside (gentamicin, tobramycin). Of a total of 45 cases, 34 were exclusively treated with fosfomycin (2 g by the intramuscular route and 2 g by the oral route) and 11 cases were treated with a double association of fosfomycin with a β-Lactamin (carbenicillin or amoxycillin) or an aminoglycoside (gentamicin), after having studied the bactericidal activity of the association in vitro. The clinical and bacteriological results were verified 4 weeks after the conclusion of the treatment and showed that there was an eradication of the urinary infection in 34 cases (75.55%), relapses in 6 cases (13.33%) and reinfections in 5 cases (11.22%). These results would seem to be favourable with regards to hospital infections and with respect to organisms that are considered to be very little sensitive or resistan