With increasing resistance to currently used antibiotics, antibiotic combinations are being resorted to. The present study deals with five children with complicated urinary tract infection (UTI) whose urine cultures grew multidrug-resistant (MDR) organisms. In all of these five cases, MDR organisms were the causative agents for UTI and the currently available antibiotics, including colistin, were ineffective, although the organisms were sensitive in vitro. In all of these cases, the isolates reverted to being susceptible to the quinolones and cephalosporins tested, namely ceftriaxone and ceftazidime. All were treated using a combination of fosfomycin with other antibiotics, since it has no interference with other classes of antibiotics. Our observations suggest that the use of a combination of fosfomycin with either a carbapenem or an aminoglycoside in a clinical setting would be a reasonable choice to treat UTIs caused by MDR organisms, especially in complicated cases that require chronic therapy.