Bovine herpesvirus type 1 (BHV-1) was investigated by a semi-nested polymerase chain reaction (SN-PCR) and by MDBK cell culture virus isolation in organ fragments from 55 aborted fetuses collected from beef and dairy cattle herds with history of reproductive problems in the North of Paraná State, Brazil. A 425 bp amplicon of the BHV-1 glycoprotein D gene was detected in 14 (25.4%) aborted fetuses. BHV-1 was isolated in MDBK cells from the tissue of 5 (9.1%) fetuses. The specificity of positive results was evaluated by Restriction Fragment Length Polymorphism (RFLP) with Bgl I restriction of DNA amplified by SN-PCR, and by virus-neutralization and immunofluorescence with rabbit anti-BHV-1 polyclonal antibodies for virus isolated in cell culture. The results of this work demonstrate the importance of using other diagnostic techniques, like SN-PCR, for BHV-1 detection in organ fragments from aborted fetuses and the high frequency of this virus in reproductive failures in Brazilian cattle herds.