Literature provides mixed results regarding the influence of large-scale sporting events on emergency department attendance. To contribute to the research on the subject, we sought to evaluate whether the broadcasting of major tennis tournaments, one of the most popular sports in Switzerland, has an impact on patient admission rates in emergency units in Geneva including 1) type of match 2) the role of a Swiss player, 3) degree of triage, 4) reason of attendance and 5) age of patients. Admission rates between periods with tennis matches regarding the semi-finals and finals of 3 major tennis tournaments were compared to equivalent periods without matches from May 2013 to August 2017. Patient admission data was retrieved retrospectively from administrative databases of two Outpatient Emergency Units in Geneva. Patients' admission rates in periods with and without a tennis match were investigated using a negative binomial regression model with mixed effects.