Since ventricular arrhythmias are a common cause of sudden cardiac death (SCD), treatment for ventricular arrhythmias is the target area of interest in research field. Among different means to prevent ventricular arrhythmias, catheter ablation (CA) has emerged as an effective therapeutic method. CA can decrease the likelihood of SCD in the following arrhythmia categories: 1) idiopathic ventricular fibrillation (VF) that is usually triggered by premature ventricular beats originating in the Purkinje fibres; 2) VF in subjects with structural heart disease, especially after myocardial infarction, that is triggered by premature ventricular beats from surviving Purkinje fibres; 3) Brugada syndrome in which modification of an epicardial substrate in the right ventricular outflow tract might be the most promising strategy; 4) recurrent monomorphic ventricular tachycardias in the setting of structural heart disease; 5) ventricular preexcitation in which CA appears to be a method of choice in high risk patients, regardless of the presence or absence of symptoms. In conclusion, CA is a therapeutic method that may prevent SCD in different subsets of patients. Better understanding of mechanisms and substrates may further improve the rate of success and/or broaden such prophylactic indications.