The thymidine kinase (TK) gene from camelpox virus has been cloned using the polymerase chain reaction (PCR). The oligonucleotides used in the PCR amplification were based on residues conserved amongst the orthopoxviruses on the 5' and 3' sides of the TK gene. The oligonucleotides were also designed to contain HindIII cleavage sites to facilitate subsequent cloning. A fragment of approximately 700 base pairs was amplified from camelpox virus infected tissue culture cells. This fragment was then cleaved with HindIII and cloned into the M13mp19 sequencing vector which had also been cut with HindIII. The nucleotide sequence of the TK gene was then determined and compared to other poxvirus TK sequences. The possibilities of producing TK- camelpox virus vaccines and of using camelpox virus as a vaccine vector for the expression of genes from other camel pathogens are discussed.