Electrophoretypes of 107 rotaviral isolates collected in Tbilisi for 18 months revealed seven patterns from which 4 were "long" and 3 "short". The "long" electrophoretypes represented 74.8% of total number of the isolates analysed. One of the "long" electrophoretypes dominated for the whole investigation period. Differences in the seasonal distribution of the isolates with various electrophoretypes were demonstrated and appearance of rotaviral isolates was registered with a "short" electrophoretype which had never been detected before.