Of 50 cases epidemiologically studied as neonatal purulent meningitis offended mainly by E. coli (1), suspected E. coli (5) and the other nonenteric pathogens from 1965 to 1975, all of the 29 survived cases (58%) were followed in the neurological and statistical follow-up study on an average 6 years afier discharge. Peaks for the annual and monthly incidence were unremarkable, but males (34) were affected more than females (16). Spinal fluid pleocytosis over 100 per cubic mm occurred in 98%. Increased spinal fluid protein above 401mg% was found in 32%, and severe to mild hypoglycorrhachia in 78% of cases. Severe hypoglycorrhachia occurred more in the age group of 16 to 45 days than the other, while mild hypoglycorrhachia, in contrast to severe hypoglycorrhachia and euglycorrhachia, exclusively in the culture negative group. The rate of positive culture was 50%. Eighty-two percent of cases hospitalized within 5 days, and 78% discharged or died within 1 month. Fever (88%) was common in the nonenteric or the cultute negative group, seizures (78%) in the older age group of 16 to 45 days, meningeal signs (40%) mostly in the age group beyond 1 month and also exclusively in the group of short-term hospitalization, cough (18%) in the group of long-tern hospitalization and hydrocephalus (6%) was only in the enteric group. The older group of 16 to 30 days mostly associtaed with postnatal infection (24%), while the young group before 15 days was with perinatal complication (16%). Two to three kinds of antibiotics were used together for 92% of cases who were severely retarded or almost normd regarding the motor function in follow-up. The case fatality varied among different seasons, patient's ages, levels of spind fluid protein, durations of hospitalization, and also the presence or adsence of cough and subdural effusion. Of 29 survivors, completely normal were 24.1%, almost normal except lisping speech 3.4%, abnomal schooling 27.6%, unable to attend school because of the mild hard neurological signs and epileptic seizures 20.7%, and bedridden 20.7% of cases among whom half were potentially fatal. Symptomatologically, we found hard neurogical signs including 55.2% of cranial nervepalsy as well as 34.4% of abnormal muscle tone, 13.8% of hydrocephalus, 13.8% of microcephalus, 27.6% of epileptics, and 20.4% fopossible hearing impaiment. The electroencephalograms, Bender Gestalt test, behavior, motor and the communictation were also extensively examined in the follow-up study. The motor, communication skill, behavior, EEG quotient ant the overall score were statistically analyzed to be influenced by one or more of the following factors: subdural effusion, hydrocephalus, epileptic seizures, numbers of antibiotic combination, the duration of hospitalization and days between onset and admission etc. The accumulated, survival rate was 57%% at 1 year, 55% 2years, 53% 6 years, and 51% 7 years after discharge. The status of developmental milestones at one year of age was one of the most reliable cues for the evaluation of the future neurological condition.