Method for the transcription based amplification of a double stranded target HBV nucleic acid sequence starting from HBV DNA optionally present in a sample, comprising the steps of, - incubating the sample, suspected to contain HBV, in an amplification buffer with • one or more restriction enzymes capable of cleaving the HBV DNA at a selected restriction site, said restriction enzyme creating a defined 3' end of one of the HBV DNA strand, • a promoter primer, said promoter primer having a 5' region comprising the sequence of a promoter recognized by a DNA-dependant RNA polymerase and a 3' region complementary to the defined 3' end of the DNA strand, and • a second or reverse primer, having the opposite polarity of the promoter primer and comprising the 5' end of the said target sequence, - maintaining the thus created reaction mixture under the appropriate conditions for a sufficient amount of time for a digestion by the restriction enzyme to take place, - subjecting the sample thus obtained to a heat treatment at a temperature and time sufficient to inactivate the restriction enzyme and to render at least partially a double strand single stranded, - adding the following reagents to the sample: • an enzyme having RNA dependent DNA polymerase activity, • an enzyme having DNA dependent DNA polymerase activity, • an enzyme having Rnase H activity, • an enzyme having RNA polymerase activity, and - maintaining the thus created reaction mixture under the appropriate conditions for a sufficient amount of time for the amplification to take place. - incubating the sample, suspected to contain HBV, in an amplification buffer with • one or more restriction enzymes capable of cleaving the HBV DNA at a selected restriction site, said restriction enzyme creating a defined 3' end of one of the HBV DNA strand, • a promoter primer, said promoter primer having a 5' region comprising the sequence of a promoter recognized by a DNA-dependant RNA polymerase and a 3' region complementary to the defined 3' end of the DNA strand, and • a second or reverse primer, having the opposite polarity of the promoter primer and comprising the 5' end of the said target sequence, • one or more restriction enzymes capable of cleaving the HBV DNA at a selected restriction site, said restriction enzyme creating a defined 3' end of one of the HBV DNA strand, • a promoter primer, said promoter primer having a 5' region comprising the sequence of a promoter recognized by a DNA-dependant RNA polymerase and a 3' region complementary to the defined 3' end of the DNA strand, and • a second or reverse primer, having the opposite polarity of the promoter primer and comprising the 5' end of the said target sequence, - maintaining the thus created reaction mixture under the appropriate conditions for a sufficient amount of time for a digestion by the restriction enzyme to take place, - subjecting the sample thus obtained to a heat treatment at a temperature and time sufficient to inactivate the restriction enzyme and to render at least partially a double strand single stranded, - adding the following reagents to the sample: • an enzyme having RNA dependent DNA polymerase activity, • an enzyme having DNA dependent DNA polymerase activity, • an enzyme having Rnase H activity, • an enzyme having RNA polymerase activity, and • an enzyme having RNA dependent DNA polymerase activity, • an enzyme having DNA dependent DNA polymerase activity, • an enzyme having Rnase H activity, • an enzyme having RNA polymerase activity, and - maintaining the thus created reaction mixture under the appropriate conditions for a sufficient amount of time for the amplification to take place.