In order to establish the rate of spontaneous resolution of congenital obstruction of the nasolacrimal duct, 50 infants, referred from a local pediatric group practice over a period of five years, were followed from the time of first symptoms until 8 to 13 months of age. Among the 50 infants, 65 nasolacrimal ducts were blocked and 58 ducts in 44 patients opened spontaneously. Only seven ducts in six patients required probing for relief of the obstruction. During the same period another seven patients from various referral sources were seen because of noninflammatory swelling of the lacrimal sac at birth. These patients were also found to have nasolacrimal duct obstruction, but early surgical intervention was required in six of the seven patients to relieve the distention of the sac.