Conditions for transformation of the solventogenic anaerobe Clostridium beijerinckii NRRL B-592 with plasmid DNA via electroporation are described. Shuttle plasmid pHR106 and two derivatives constructed in this study were transferred and were expressed in this organism. One recombinant derivative of pHR106 was constructed by separately subcloning the clostridial tetracycline (tetP) resistance genes into pHR106. The second vector conferring erythromycin resistance was obtained via in-vivo recombination. The new constructs, termed pRZL and pRZE respectively, were then transferred to C. beijerinckii in order to evaluate their potential as shuttle vectors. The recombinant plasmids were shown to transfer to C. beijerinckii and were expressed as autonomously replicating vectors. The use of these plasmids as cloning and shuttle vectors for C. beijerinckii is discussed.