Objective: The frequency of residual shunting or recanalization was investigated in patients in whom a persistently patent arterial duct had been doubly ligated and transfixed during surgical closure. Methods: We investigated in retrospective fashion for any residual shunting 325 patients who, between January 1990 and December 2004, had undergone surgical double ligation and transfixion of a persistently patent arterial duct. Shunting was discovered in 10 patients, of whom four male and six female. Results: Of those with residual shunting. 4 patients had initially exhibited only persistent patency of the duct, while the other 6 had associated mild cardiac lesions. The mean age at operation was 5.5 years, with a range from 0.5 to 17.9 years. Postoperatively, the mean period for detecting the residual shunt was 22.8 months, with a range from 2 days to 72 months. The frequency of residual shunting amongst our patients, therefore, was 3.1%. We detected the residual shunt by colour-flow Doppler mapping in all patients, although a continuous murmur was heard in only one patient on physical examination. Conclusion: Our findings suggest that clinical sensitivity of detecting residual shunting subsequent to surgical closure of the persistently patent arterial duct is low, and hence that colour-flow Doppler interrogation should be a part of follow up. Residual shunting, or recanalization, may occur even after double ligation and transfixion of the duct. Since the residual flow may emerge after months, or even years, follow-up is needed for longer periods.