An epidemiological survey based on sorology for antibodies to bovine herpesvirus 1 (BHV 1) was performed in Pernambuco State, Brazil. Two hundred and eighty two samples from 18 herds were tested by serum neutralization test (p 37/24) and 69.5 per cent were positive. A positive association between age and seropositivity by BHV 1 was observed. These findings indicate that BHV 1 is widely disseminated in the studied population