INTRODUCTION: The risk of post-procedural urinary tract infection (ppUTI) after retrograde urethrogram (RUG) has not been well quantified. Prophylactic antibiotics may reduce the risk, but must be weighed against the risks of antibiotic resistance. Prior research has shown that this risk is variable after voiding cystourethrogram (0-42% reported ppUTI rate) and appears to be low after urodynamics (0-4.8%) but this risk has not been well documented for patients undergoing RUG. OBJECTIVE: We aimed to (1) describe the rate of ppUTI after RUG, and (2) examine factors associated with use of antibiotics at the time of RUG. STUDY DESIGN: We conducted a retrospective cohort study of children undergoing RUG at two hospitals January 1, 2004, to December 31, 2014. ppUTI within 7 days was measured. Antibiotic prophylaxis was determined. Relationships between clinical characteristics and receipt of pre-procedure antibiotics were evaluated using univariate statistics. RESULTS: Forty-two patients (100% male, median age 11.7 years) underwent 47 RUGs. Indications included trauma (27%), hypospadias (17%), and non-hypospadias (27%) stricture. Study indication and antibiotic administration practices are illustrated in the Figure. Three patients (6.4%) had a history of posterior urethral valves (PUV); one had neurogenic bladder (NGB) (2.4%). Two (4%) studies were performed within 30 days of a clinical UTI and 11% had a positive urinalysis or culture within 30 days pre-RUG. UTI in the 30 days before RUG was not associated with antibiotic prescription (p > 0.99). One child (2.1%; 95% CI 0-6.3%) had a ppUTI: a 7-year-old, uncircumcised male with a history of PUV and voiding dysfunction who was asymptomatic at the time of RUG. DISCUSSION: Although the risk of ppUTI after RUG appears to be low, the rare occurrence of an iatrogenic UTI can lead to high cost and patient morbidity, particularly in cases similar to our patients who required inpatient admission for intravenous antibiotics. To help balance the risk of UTI with the associated healthcare costs and morbidity with the concerns about antibiotic overuse and potential exposure to drug reaction, data from this study may inform future development of evidence-based guidelines targeting only patients at highest risk for ppUTI with antibiotic prophylaxis. CONCLUSIONS: The risk of ppUTI after RUG is low. Antibiotic prophylaxis was unrelated pre-RUG UTI in our population. These results indicate the need for pre-procedural antibiotic prescribing guidelines, and suggest that routine antibiotics prior to RUG are not indicated unless the patient has another indication for antibiotics.