Knowledge about college costs was studied with a sample of parents and their teenage children. The sample included high school sophomores and seniors who completed the 1980 High School and Beyond survey. Responses to a mail survey were obtained from a national sample of 6,564 parents. Overall, data from parents and students suggest that parents are not especially knowledgeable about the expenses for fees, tuition, and books in different types of schools. The percent of respondents answering "don't know" was high, considering that the question asked only for an estimate of educational costs. Parents were more knowledgeable than their children, however, especially in the sophomore year, and children whose parents were more knowledgeable were also more knowledgeable. The level of the parents' knowledge depended most strongly on the parents' own education. Those with college expectations for their children were also somewhat more knowledgeable. Race and family income had some effect on knowledge of costs. It is suggested that to the extent that lack of information is associated with socioeconomic status, the goal of equal access to educational opportunities will not be realized. (SW)