The purpose of this prospective pilot study was to (1) evaluate the role of pyuria in predicting the progression from asymptomatic to symptomatic urinary tract infection (UTI) in spinal cord-injured patients who undergo sterile intermittent bladder catheterization and (2) evaluate the impact of treating asymptomatic UTI on this progression. Twenty hospitalized patients were randomized to either the treatment group (10 subjects) or the control group (10 subjects). Weekly urine samples were obtained for quantitation of bacterial growth and pyuria. Neither the level nor the trend of pyuria helped predict the imminent progression to symptomatic UTI. Thirty percent of patients in the treatment group developed symptomatic UTI vs 70 percent of patients in the control group; it took a significantly longer time for patients in the treatment vs control group to develop symptomatic UTI (median number of days: 72 vs 7, respectively; p < 0.003). Further analysis of the long-term impact of antibiotic treatment of asymptomatic UTI is warranted.