In this seminar by a member of the house staff of the Department of Pediatrics of the University of Colorado, attention is called to several interesting new observations regarding the problem of rubella in the pregnant woman. Although the physician now has more specific information on which to base a prediction as to the likelihood of complications in the offspring, some reports suggest that difficulties may occur not only in women who develop rubella during the first part of pregnancy, but also in presumably immune women who are exposed to the disease without developing any clinical manifestations.As in other seminars in this series, this one attempts to review recent developments in a subject of particular interest to the physician in practice and in training.