BACKGROUND. Studies typically find that predisposing and enabling factors strongly predict dental utilization, but that need factors do not. However, few longitudinal studies have been conducted, and few have comprehensively measured dental need. OBJECTIVES. To describe the paradox of dental need, and to test three hypotheses regarding need and dental care use. MATERIALS AND METHODS. An observational study that included 873 persons who participated for interview and clinical examination at baseline and 24 months, with 6-month telephone interviews in between. RESULTS. Persons who entered the dental care system during follow-up were actually in better dental health than those who did not. The ability of need factors to predict dental care use, and in which direction, varied with how dental need and the dental care use outcome were measured (eg, care of any type, problem-related care, to receive a dental cleaning, to get a dental checkup). CONCLUSIONS. A substantial number of dental problems remained or developed among the population that did not enter the dental care system. The paradox of dental need has three components: (1) need predicts dental care use but is dependent upon how need is measured; (2) however, persons with a higher probability of new dental problems are actually less likely to seek dental care; and (3) self-reported disease and oral pain are associated with a higher likelihood of seeking care, whereas clinically-determined need, such as chewing difficulty, lower self-rating, and satisfaction with oral health, are actually associated with a lower likelihood, the former direction being the predominant and expected direction. © 2003 Lippincott Williams & Wilkins, Inc.