When the normal physiological process of deciduous tooth exfoliation and eruption of its successor is disrupted, a series of changes are observed in the dental arches. The aim of the study was to evaluate the amount of changes in arch length after the premature loss of deciduous molars. The sample consisted of 82 children, 53 without premature loss and 29 with premature loss of either deciduous first or second molar or both, unilaterally. A reduction in arch length was observed both in the maxilla and mandible at the molar region and an increase in arch length at the canine region in the mandible. Reduction in arch length was due to mesial migration of the molar and the increase in arch length was due to the distal migration of canine. It was seen that arch length reduction was more in maxilla as compared to the mandible and that distal drifting of canine was observed only in the mandible.