Eradication of polio outbreaks and tetanus neonatorum mortality, as well as lowering Egyptian infant mortality to less than 50 per 1000 live births, were specific goals to be achieved by the year 2000. National television immunization campaigns were launched to persuade mothers to change their attitude and vaccinate their children against the killer diseases. This study investigates the effects of these campaigns on mothers' knowledge, attitude, and behaviour regarding immunization in Egypt. A comparative study was conducted among three groups of mothers who have a child three to twelve months of age. A total of 158 mothers were selected, by systematic random sample technique (1:2), from the part of Kolosna village, in Upper Egypt, which is supplied with electricity, to constitute the viewer group. From the other part of the same village, which is not yet supplied with electricity, all mothers (98) were selected, representing the non viewer group. Another 76 mothers were selected from two prestigious social clubs in Cairo, to represent a second control group of known social class and educational level. Through comparing mothers' knowledge, attitude, and behaviour between the viewer and the non viewer groups, the effect of television immunization messages can be illustrated. Similarly, comparing the village viewer with the Cairo viewer group determines the effects of some intervening factors such as educational level, health professionals, or experience With a structured interview, mothers in the viewer group showed a significant positive and stable attitude and behaviour towards immunization, as well as more correct knowledge when compared with the non viewer group, demonstrating the positive role of television in child health promotion. Television enhances mothers' efficiency to use the available health services and promotes their perceived control over children's health. Health professionals, experience, and social support can potentiate the television's positive role. Educational level, occupation, baby's sex, or mothers' age are insignificant factors in changing mothers' attitude and behaviour.