In this study, we present the results of 40 consecutive patients who underwent Senning procedure between September 1983 - March 1992. Mean age at operation was 28 months (range 4 months to 9 years). Early postoperative mortality was 9.5% (2/21, 70% confidence limit; 3,1% - 21%) in the patients with simple TGA. Seven of 19 patients with complex TGA (TGA + VSD + PH/PS) died in the early postoperative period. Persistant pulmonary hypertention was the main reason for early deaths in the patients with TGA + VSD + PH (5/9,55%, 70% CI:38%-75%). In the group of TGA + VSD + PS, 2 patients were died (20%, 70% CI; 7%-40%). Mean follow up is 44 months (2 to 102 months). Only one late death was happened due to endocarditis. All surviving 30 patients are doing well. Their periodical examinations and Doppler echocardiographic controls showed neither systemic nor pulmonary venous obstruction. They are in NYHA functional class I or II. Because of the decreased early mortality rates and the satisfying medium / long term results Senning operation will continue to take an importont place for the surgical treatment of TGA.