The purpose of this study was to identify the effects of television (TV) on preschoolers, their TV viewing patterns and the conditions under which they watch TV, taking into consideration their different socioeconomic and regional backgrounds. The survey instrument was a questionnaire with 23 closed-ended questions, given to parents whose children attended 10 randomly selected preschools in northern Greece. The overall survey completion rate (returned surveys 355 out of 400) was 87.7%. Most of the preschoolers watched two hours of TV daily, which was exceeded during the weekend and the holidays. Most parents intervene in the choice of programs their kids watch and they discuss them together. The frequency of this parental mediation is related positively to the family's socioeconomic status, with those of the upper echelons intervening and initiating discussions more often than the lower ones. Preschoolers were greatly influenced by TV, which was expressed through persistent requests for their parents to buy them the advertised products they saw. Ours findings suggest that it is important for parents to manage their preschoolers' TV viewing by making a weekly plan as to what programs are appropriate for their age and how much time overall may be spent on TV viewing. (Contains 9 figures.)