A survey of 67 pregnancies in 51 professional women (physicians, psychologists, nurses, administrators, etc.) revealed the occurrence of symptoms of cognitive dysfunction such as forgetfulness, disorientation, confusion and reading difficulties in 28 pregnancies occurring in 21 women. These were unrelated to such factors as age of delivery, percentage weight gain, the baby''s sex or birth weight, alcohol consumption, smoking, a history of migraine or allergy or other symptoms occurring during pregnancy such as sleepiness and lack of concentration, irritability, loss of interest in job or nightmares. Nor was there any correlation with hypertension, proteinuria, glycosuria, ketonuria, anemia, or morning sickness. Furthermore, these cognitive disturbances were not related to depression or sleep deprivation. Despite these symptoms, none of the women suffering from them were forced to interrupt their professional activities during pregnancy. The syndrome of benign encephalopathy of pregnancy should be recognized so that simple precautions can be taken to prevent any interference with professional or other activities. The etiology of the syndrome is unknown.