The influence of selected factors, viz. age and educational level of parents, income and type of family on motor and mental abilities of urban and rural infants of 6-12 months was studied. The results revealed that in urban group, age of the mother influenced the psychomotor development but not mental development, while age of the father was negatively and significantly related to both the developmental indices. In case of rural group age of the parents did not influence the developmental indices. Education level of parents had strong influence on both the developmental indices of the urban infants, while in rural group, education level of father was not related to psychomotor development. There was a significant and positive relation between income of the family and developmental indices, while in rural group, no relation was observed with psychomotor development. Type of family to which the infants belonged did not influence the developmental indices, but in rural group it influenced the psychomotor development.