The role or function that dogs and cats fulfill as pets in families with preschool-age children was examined in terms of pet prevalence, their relationship to animal fears, and their association with imaginary companions. The sample consisted of 37 children, three years nine months to five years nine months of age, in the Colorado State University Preschool Laboratory and their mothers. Mothers' data was collected by means of a questionnaire and an interview was conducted with the children. Measures used to determine the level of significance were the single-variable chi-square test, and the chi ... square contingency table. The first hypothesis, that there would be no difference between the prevalence of dogs and cats and any other pet in the preschooler's family, was rejected on the basis of the single variable application of the chi-square test. Dogs were revealed to be the preferred pet. Hypothesis two, relating mothers' fear and children's fear of dogs and cats, showed no statistical significance, therefore the null hypothesis was not rejected. However, statistically significant findings indicated that children who had an experience with a pet were less fearful of dogs and cats. The third hypothesis, which examined selection of pets and non-pets as imaginary companions was rejected. Statistical analysis revealed that children chose non-pets as imaginary companions more often than they did pets. Conclusions based on the study may be applicable to similar samples. There is a high incidence of pet possession among preschool children. Children can and do assimilate realistic aspects of their pets, and relate positively to types of pets that are similar to the ones they have presently or previously owned. Those children who have an experience with a pet are less likely to be fearful of dogs and cats, though the effects of their mothers' fear of dogs and cats were negligible. Data on the role of the pet as an imaginary companion suggested that the pet experience needs to be of a concrete tangible nature to be meaningful to young children, rather than an imaginary one. Pets in families are more likely to play the role of family pets rather than the role of pets to any single family member.