Among 101 nursing home residents with suspected urinary tract infection (UTI), we determined the negative predictive value of dipstick testing for leukocyte esterase and nitrite to be 100% (95% confidence interval, 74%-100%), compared with laboratory evidence of UTI (greater than 10 white blood cells/mm(3) on urinalysis and greater than 100,000 colony forming units/mL on urine culture). Nursing home dipstick testing effectively excluded the possibility of UTI.