Percutaneous closure of a patent foramen ovale (PFO) was performed in 98 consecutive patients (mean age 52.5 +/- 13 years, 61 women). Indications included recurrent transient ischaemic attack (47%), cryptogenic stroke (34%), peripheral embolism (11%), disabling migraine with aura (4%), professional scuba diving (1 pt) and severe platypnea-orthodeoxia syndrome (1 pt). Each PFO was characterized by transesophageal echocardiography (TEE) according to anatomy, degree of shunt (1-mild, 2-moderate, 3-severe), right atrial anatomical features relevant for PFO closure (such as presence of an Eustachian valve, Chiari network, lipomatosis or absence of septum secundum) with a new classification scheme. According to this classification successful device delivery was obtained in 100% of pts. Major complications included heparin-induced thrombocytopenia in 1 pt and device dislodgment in 1 pt; minor complications were mostly related to the catheter introduction site (2 pts) and mild immediate shunt (2 pts). In conclusion, percutaneous PFO closure based on strict anatomic criteria is a safe procedure with minimal periprocedural complications.