Rapid and reliable detection of viral pathogens is critical for the management of the diseases threatening the economic competitiveness of the swine farming industry worldwide. Molecular beacon assays are one type of real-time polymerase chain reaction (PCR) technology capable of fast, specific, sensitive, and reliable viral detection. In this paper, the development of molecular beacon assays as novel tools for the rapid detection of Aujeszky's disease virus, African swine fever virus, porcine circovirus type 2 and porcine parvovirus is described. The assays are capable of rapidly detecting 2 x 10(1) copies of target and are linear between 2 x 10(9) and 2 x 10(2) copies. They can detect virus specifically in clinical samples such as whole blood, serum and tissue. In comparison to conventional PCR they are either as sensitive or more sensitive. As such these molecular beacon assays represent a powerful tool for the detection of these viruses in swine.