Fifteen professional football players have been examined with basal electrocardiography, M-mode echocardiography, bicycle ergometry, Holter dynamic electrocardiography; in six of them also, the electrocardiogram has been recorded by during a match. The aim of the research was to evaluate, by non-invasive tests, the cardiovascular status of an athletic team, with particular consideration to rhythm disturbances. The methods employed have given valuable informations. The echocardiographic investigation has frequently shown left ventricular dilation and/or hypertrophy. Dynamic electrocardiography has revealed in many subjects rhythm and conduction disturbances. No athlete has displayed severe rhythm disturbances during the bicycle ergometer test, except one, who had paroxysmal ventricular tachycardia, of complex etiopathogenetic and prognostic significance. Telemetric recording has been very useful to follow the heart action during a match, but its use was often hampered by technical difficulties.