Atypical atrial flutter is a rare supraventricular tachyarrhythmia which is extremely challenging to visualize using well known mapping systems. New approach using the ultra-fast, high resolution 3D mapping systems could be a step forward in understanding and treatment of this arrhythmia. We report a case of a 54- year- old man with paroxysmal, atypical atrial flutter who was admitted to the tertiary cardiology centre. The patient underwent pulmonary vein isolation due to atrial fibrillation and as a result of the intervention he has developed atypical atrial flutter. Arrhythmia was previously treated with electrical cardioversion but without any success. An ultra-fast, high-density 3D mapping system (Rhythmia, BostonScientific) was used to determine the arrhythmia localization. An ablation was done with a 8.5F basket mapping catheter equipped with 64-low noise electrode. This system has allowed for a precise and adequate mapping thus enabling the patient’s arrhythmia to convert into the sinus rhythm.