Meningococcal sepsis with cardiovascular manifestations is one of the leading causes of pediatric intensive care admission (14.85%) in our area. We carried out a two phase study over period of 10 years from 1979 to 1988, involving a retrospective analysis of clinical and analytical manifestations in order to determine a prognostic score of the severity of meningococcal infections in our area. A total of 86 cases were studies over a two year period. After establishing the prognostic score, we applied a previously assayed therapeutic protocol, based on the number of criteria of severity, in 170 children selected as having the same criteria. The factors of seriousness considered were: Appearance of the first symptoms less than 12 h. previously, appearance of petechia less than 6 h. previously, hyperthermia, shock at admission, absence of meningitis, fulminating course of purpura and convulsions, leukopenia less than or equal to 5,000 mm3, prothrombin activity less than or equal to 45%, platelets less than or equal to 75,000 mm3, fibrinogen less than or equal to 250 mgrs% and FPD greater than 40 micrograms/ml (p less than or equal to 0.01 (CHI SQUARE]. In the first phase of study, overall mortality was associated with the presence of three criteria, and was highest when more than seven criteria were present. The results indicate that mortality from meningococcal sepsis is linked to fulminating deterioration of hemodynamics and DIC.(ABSTRACT TRUNCATED AT 250 WORDS)