The Digene Chemiluminescent Molecular Hybridization Assay for the detection and quantitation of hepatitis B virus DNA (HBV-DNA) in serum was tested by comparing it with the Abbott HBV-DNA assay, which uses a radiolabelled probe. For the values of clinical interest, a relationship was found between the results (in pg/ml) from the Digene (Y) and the Abbott (X) assays: Y = 7X + 5. The cut-off value to obtain positive results with a specificity of 100% (as determined by polymerase chain reaction), was found to be 15 pg/ml for the Digene test and 10 pg/ml for the Abbott test. It was concluded that the Digene Chemiluminescence Assay is a fast convenient test, which is suitable for routine use.