This study examined the distribution of organisms and their antimicrobial resistance in patients admitted due to acute bacteremic and non-bacteremic community-acquired urinary tract infection (UTI). During a period of 1 year and 1 month, a total of 201 patients and 253 bacterial isolates were studied. Fever higher than 38.5 degrees C was significantly more common in the bacteremic group than the non-bacteremic group (68% vs 48%; p<0.05). Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Proteus mirabilis were the most common organisms isolated. E. coli was the leading pathogen and it was significantly more predominant in bacteremic UTI than non-bacteremic UTI (73% vs 49%; p<0.01). Bacteria other than E. coli (i.e., K. pneumoniae, P. aeruginosa, Proteus spp., Morganella morganii, Enterobacter cloacae, Citrobacter spp., Acinetobacter baumannii, Serratia marcescens, and Providencia spp.) were more common in non-bacteremic UTI than bacteremic UTI (44% vs 22%; p<0.01). E. coli isolated from both bacteremic and non-bacteremic patients had a high rate of resistance to ampicillin (80%), cephalothin (59%), gentamicin (29%), piperacillin (61%), trimethoprim-sulfamethoxazole (56%), amoxicillin-clavulanic acid (34%), and ticarcillin-clavulanic acid (36%). Isolates of P. aeruginosa, K. pneumoniae, and Proteus spp. from the non-bacteremic group showed a higher proportion of resistance to extended-spectrum cephalosporins, aminoglycosides (netilmicin and amikacin) and ciprofloxacin. The emergence of a high rate of resistance to commonly used antimicrobials (ampicillin, cephalothin, gentamicin, trimethoprim-sulfamethoxazole, piperacillin, amoxicillin-clavulanic acid and ticarcillin-clavulanic acid) may have an impact on the antibiotic treatment of patients admitted due to acute community-acquired bacteremic or non-bacteremic UTI in Taiwan. Further studies are needed to clarify the impact of antimicrobial resistance on the outcome in these conditions.