Abstract Introduction and hypothesis The Global Prevalence Study of Infections in Urinary tract in Community Setting (GPIU.COM) includes epidemiological aspects of acute cystitis (AC) in women in Germany and Switzerland. The primary study relates to the German version of the Acute Cystitis Symptom Score (ACSS), a self-reporting questionnaire for self-diagnosis and monitoring the symptomatic course of AC in women. The current study aimed to analyze the validity and reliability of the German ACSS in German-speaking female patients with AC in Switzerland. Methods Anonymized patient data were collected and analyzed from women with AC at the first visit (diagnosis) and follow-up visits as baseline and controls, respectively. Data from 97 patients with a median age of 41 years underwent analysis. Psychometric and diagnostic characteristics of the ACSS were measured and statistically analyzed. Results Average internal consistency of the ACSS resulted in a Cronbach’s alpha (95% CI) of 0.86 (0.83; 0.89) and did not differ significantly between the Swiss and German cohorts. Diagnostic values of the ACSS for the Swiss cohort were relatively lower than for the German cohort, possible due to discrepancies between definitions of UTI in national guidelines. Conclusions The analysis showed that the German version of the ACSS is also suitable for use in the German-speaking female population of Switzerland. Minor differences in definitions of AC between German and Swiss guidelines explain the observed discrepancies in diagnostic values of the ACSS between cohorts.