In a study of 160 Korean infants aged between one and six months, average time spent sleeping decreased, and total daily maternal periods of contact increased, with age (though not significantly). The increment of total periods spent by the infant alone was significant, but the decrease of crying duration was not. There was no definite clustering of crying during the evening hours. The most common responses of mothers towards their baby's crying were feeding, contact and no response, in order of frequency. Compared with Western studies, the duration of crying of Korean infants was shorter and the time of holding and/or close contact with mothers longer, and colic was not found in this study. These findings may be related to the caring practice of mothers.