Children are the future of society and their mothers are guardians for that future, therefore their knowledge, attitude and practice regarding four important aspects in the health of their children (antenatal care, natal and newborn care, feeding and weaning and the communicable diseases prevention and control) is of high importance especially taking in consideration the poor previous and current situation of the health system in Iraq (Save the children, 2007). This was a cross section study conducted from May till the end of November 2007 to estimate the Modernity of Knowledge, Attitude and Practice of the mothers of under five children and its effect on the child health on one hand and the effect of the socio-demographic characteristics of the mother on it on the other hand. The study was done through the exit interview of 932 mothers of under five children visiting eight primary health care centres in four sectors in the urban area of Baghdad city.The results of the study showed the following: Sixty five percent of the mothers were housewives, sixty nine percent of them were (20-35) years old, one quarter of them were married before the age of eighteen, eighteen percent of them have not finished primary education, and one third of them delivered after less than (18) months of the previous delivery.The study showed also that most of the mothers had lack in the Knowledge, Attitude and Practice in mentioned aspects of the health of their children.The child health modernity was influenced by the socio- demographic factors of the mother and their different parameters while the child health modernity influenced the health and development of the under five child. It is recommended to use the Child Health Modernity Scale for the estimation of strengths and weaknesses in child health programs and that higher quality and quantity of health education be provided by the health workers to the mothers to improve the general health status of the Iraqi children.