The promotion of oral health in the early years of life is important to promote well-being and prevent early childhood cavities. The aim of this work was to determine the level of knowledge, beliefs, and perceptions of a group of Mexican university students in the area of health on early childhood cavities. A questionnaire was applied to students (N = 515) of the tenth semester of the degrees of Nursing, Medicine, and Dentistry based on the "Health professional’s guide to pediatric oral health management, "Guide for oral health risk assessment training" and "Dental Beliefs Scale N". The x2 test was used to analyze the association of variables among students. Of the total respondents, 80.7% scored regular knowledge, 13.3% good, and 6% poor. Association was observed in the belief of knowing how to treat problems of tooth decay (x2 = 0.003, p < 0.05), how to perform oral hygiene on children (x2 = 0.025, p < 0.05) and in perception between the information and bachelor’s degree (x2 = 0.012, p < 0.05). Educational programs in the area of health must find ways to introduce topics on best practices in child oral health, particularly those related to dental cavities and early childhood cavities.