Background: There is a limited number of studies of consecutive patients suspected of having arrhythmogenic right ventricular cardiomyopathy (ARVC) as established by the Task Force report [Br Heart J 1994;71:215-218]. Objective: The aim of this study was to describe a population of ARVC patients who were referred to a university hospital for thorough clinical evaluation of right ventricle arrhythmia using both noninvasive and invasive procedures. Methods: In a prospective design 48 patients suspected of having ARVC underwent cardiac magnetic resonance imaging (MRi), contrast ventriculography, an electrophysiological test and endomyocardial biopsies from the lower septum. Results: A diagnosis of ARVC was established in 30 patients (age 40 ± 2 years, mean ± SEM) and in one third of the patients, intense running, cycling or rowing provoked palpitations and syncope. Arrhythmias were frequent premature contractions of RV origin and/or ventricular tachycardia with a left bundle branch configuration. In 14 ARVC patients the ECG trace showed right bundle branch block or inverted T waves in right precordial leads. Contrast ventriculography demonstrated RV dilatation in 11 ARVC patients and in 18 patients the septal biopsies showed fatty tissue myocardial infiltration. In 25 patients cardiac MRi showed islands of high signal intensity indicative of RV fatty infiltration. Conclusions: ARVC is a heterogeneous syndrome and an abnormal right ventricle and arrhythmias of right ventricle origin must lead to a clinical evaluation. Cardiac MRi appears to be an important diagnostictool in patients suspected of ARVC and should be used to guide invasive procedures.