Pathogens causing BRDC in Serbia were investigated. Two herds of beef cattle with bovine respiratory disease were included, with twenty diseased calves (10 from each farm) were chosen for isolation of bacteria on artificial culture media and determination by aerobic cultivation. The most common bacterial pathogen was isolated was Pasteurella multocida. Diffusion method of sensitivity to antibiotics (antibiogram), revealed that Enrofloxacin and Floron were most efficient antibiotics against Pasteurella multocida isolates (100 % isolates sensitive on both antibiotics). From the all examined samples (n=20) using the method of Real Time PCR (RT-PCR and PCR) we determined the genome sequences of bovine respiratory syncytial virus (BRSV), but in none of the samples genome of bovine viral diarrhea virus (BVDV) and bovine herpesvirus-1 (BoHV-1).