Two epidemics of ECHO virus type 30 meningitis were compared with the special emphasis on the course of the disease and results of the laboratory investigations. The first epidemic occurred in 1995 and the second one in 1996. Between 20 August and 20 October 1995, thirty six children, and between 11 July and 15 October 1996, ninety one children were admitted to the Department of Infectious Diseases, Medical University of Lódź. All children were 3 to 15 years old, the median age was 9.08 years in the 1995 epidemic and 8 years in the 1996 epidemic. The common symptoms were headache, fever, vomiting and nuchal rigidity. The course of both epidemic was mild, there were no complications and serious sequelae of the disease. Typical symptoms were found more frequently in patients in 1996 epidemic. Patients in 1996 had higher CSF pleocytosis and the percentage of granulocytes in the CSF than patients in 1995. From the other side, patients in the 1995 epidemic had higher fever of longer duration than patients in the 1996 epidemic.