Several rhythm disorders related with quinolones were reported. Quinolones prolong action potential duration and QT interval via blocking the human ether-a go-go related gene (HERG) K channel. This report presents a case with hypotension and bradycardia that was assumed to be related with ciprofloxacin. A 75-year-old man with bradycardia and hypotension was referred to our outpatient clinic. He has been taking ciprofloxacin 500 mg bid for urinary tract infection. Initially, bradycardia was diagnosed in his electrocardiography (ECG). However, comparing with the previous ECGs recorded before ciprofloxacin therapy, it was concluded that the apparent bradycardia was due to the nonconducted premature atrial activities. His symptoms and bradycardia improved after discontinuation of ciprofloxacin. Quinolones have been well known to prolong the QT interval but there is no data about its bradycardia effect in the literature. We thought that ciprofloxacin caused prolongation of AV nodal or bundle branches’ refractoriness leading to conduction block of premature atrial activities. In our case, symptomatic bradycardia is probably dependent on our patient’s characteristic.