The introduction of commercially available quantitative HIV-1 RNA detection methods at the end of the last century has had a significant impact on the management of patients requiring treatment. Similarly for hepatitis C virus (HCV), clinical decision-making with respect to initiation and prolonging therapy is largely based on data from viral load assays. The methods developed in the early 1990s and further improved since then still have significant drawbacks. For example, they are labor intensive, have a small dynamic range and are contamination sensitive. The development of real-time detection techniques for reverse transcription PCR has in part solved these problems. In the present review the advantages and disadvantages of the recently marketed Abbott Realtime (TM) HCV and HIV-1 viral load assays relative to their competitors will be discussed.