Forty-six children having confirmed cases of lead poisoning were hospitalized in Chicago in 1953 and 1954. This article summarizes the epidemiological and psychological findings for both years and reports on a follow-up psychological study of the first group two years after their acute illness. The same investigative procedures and psychological techniques were used in 1953 and 1954. A comprehensive report on the cases discovered in 1953 and a description of our procedures has already been published.1The clinical, laboratory, epidemiological, case history, mental, and emotional findings were very similar for the two years. Our present, larger, sample and consistent findings allow us to make more precise statements about this public health problem. Epidemiology The epidemiological data show children between 1 and 4 years of age to comprise about 90% of the cases. The same proportion reside in the poorest slum areas of the city, a few being in lower-middle-class