Background:Urinary tract infection (UTI) during acute ischemic stroke is associated with a longer hospital length of stay and unfavorable functional outcomes.Objective:We investigated the benefits of portable bladder ultrasound (PBU) scanning during acute ischemic stroke.Methods:We retrospectively reviewed patients with acute ischemic stroke from January 2011 to February 2017. Patients were divided into group 1 (PBU not available) and group 2 (PBU available), before or after the split date, April 9, 2014. Portable bladder ultrasound scanning was conducted by nurses to measure postvoid residual urine volume in patients with impaired consciousness and/or dependent ambulation.Results:In total, 1928 patients were enrolled, of whom 109 (5.7%) had UTI and 901 (46.7%) experienced unfavorable outcomes (modified Rankin scale score ≥ 3). Multivariate analysis revealed that factors that influenced UTI were age of 75 years or older, female gender, initial total National Institutes of Health Stroke Scale (NIHSS) score of 5 or higher, initial NIHSS conscious score of 1 or higher, initial NIHSS leg score of 2 or higher, and urinary catheterization. Factors influencing unfavorable outcomes were similar to those influencing UTI but further comprised UTI. C-statistic for UTI detection was 0.864 for model fitting, including significant factors in logistic regression. Compared with group 1, group 2 had a higher incidence of urinary catheterization (13.1% vs 8.2%), a lower incidence of UTI (4.0% vs 6.9%), and a shorter length of stay (11.9 vs 13.6 days).Conclusions:Portable bladder ultrasound scanning reduced the incidence of UTI and shortened length of stay. We suggest routine PBU procedures for patients with acute ischemic stroke who fulfill the AGN3 criteria for a high risk of UTI.