Approximately 75% of all perinatal mortality is attributable to preterm birth and its sequelae; therefore, the prevention of preterm birth is a major public health priority. In an effort to determine what pregnant women need to be taught about this subject, 211 pregnant women in an inner-city clinic were given a questionnaire to ascertain their basic knowledge about the subject. Among the results were that almost one-half of the women surveyed did not know how many weeks constituted a normal pregnancy and one-third did not know that neonates born preterm could have health problems. The importance of teaching these and other basic facts (which nurses might think are already known by pregnant women) is a notable finding of this research. If perinatal nurses are to effectively teach pregnant women about the prevention of preterm birth, they must target the appropriate facts and build their patients' knowledge base.