BACKGROUND: Urinary tract infections (UTIs) often lead to suboptimal antibacterial use. Pharmacists are accessible primary care professionals who have an important role to play in antimicrobial stewardship. Our objective was to evaluate the appropriateness of pharmacists’ antibacterial prescribing for patients with uncomplicated UTI. METHODS: We conducted a prospective registry trial with 39 community pharmacies in New Brunswick, Canada. Adult patients were enrolled if they presented to the pharmacy with either symptoms of UTI with no current antibacterial treatment (pharmacist-initial arm) or an antibacterial prescription for UTI from a physician (physician-initial arm). Pharmacists assessed patients; patients with complicating factors or red flags for systemic illness or pyelonephritis were excluded. Pharmacists prescribed antibacterial therapy or modified antibacterial therapy, provided education only, or referred to a physician, as appropriate. Antibacterial therapy prescribed was compared between study arms. RESULTS: Seven hundred fifty patients were enrolled (87% pharmacist-initial arm). The most commonly prescribed agents in the pharmacist-initial arm were nitrofurantoin (88%), sulfamethoxazole–trimethoprim (TMP–SMX) (8%), and fosfomycin (2%); in the physician-initial arm, nitrofurantoin (55%), TMP–SMX (26%), and fluoroquinolones (11%) were prescribed. Therapy was guideline concordant for 95.1% of patients in the pharmacist-initial arm and 35.1% of patients in the physician-initial arm ( p < 0.001). For guideline-discordant therapy from physicians, pharmacists prescribed to optimize therapy for 46% of patients. CONCLUSION: Treatment was highly guideline concordant when pharmacist initiated, with physicians prescribing longer treatment durations and more fluoroquinolones. This represents an important opportunity for antimicrobial stewardship interventions by pharmacists in the community.