Spontaneous resolution of congenital nasolacrimal duct obstruction in infancy is common. However, little is known about its course in childhood. The aim of the study was to determine the frequency of resolution with medical therapy (spontaneous resolution) in infancy and childhood, the timing and application of interventional procedures. A total of 585 infants and children, with 802 congenital nasolacrimal duct obstructions, were treated during a ten year old period, from June 1985 at StMichael's and St.Anne's hospitals in Colombo. All patients were initially treated medically (massage), and failures were subjected to probing, and when probing failed, to dilatation. Resolution with medical therapy was 86% in patients under two years, while there was a progressive decline in the success rate (27%). Success rate for initial and second probing was 78% and 100% repectively, in children over two years, while in the two to eleven year age group the overall rate was 43%, without success above eight years. There was a progressive decline in success rate with probing, with increasing age in children. Dilatation with Nettleship dilator was done in failed probing in 33 obstructed ducts, the success rate being 90%. The results suggest that in nasolacrimal duct obstruction in children under two years, probing gives excellent results (1st probing 78% , 2nd 100%). In failed probing in childhood, dilatation with Nettleship dilator is a useful alternative to complicated procedures such as intubation or dacryocystorhinostomy.