Carbon nanotubes (CNTs) have become a popular material in the field of nanomedicine. Their shape, strength and electrical conductance properties make CNTs unique from many nanoparticles and present advantages when used in biological applications. Of particular interest is the delivery of therapeutic nucleic acids (small interfering RNA, antisense oligonucleotides, etc.) into cells. The use of a nano-delivery system for nucleic acids can improve efficiency of therapeutic applications by increased cellular uptake, protection from cellular nucleases as well as rapid clearance and metabolism by the liver. However, because of structural variations resulting during fabrication and chemical variations resulting during processing required to achieve water solubility, carbon nanotube preparations are highly heterogeneous and complex. This complexity has contributed to apparent discprepencies reported in biological studies with carbon nanotube-biomolecule conjugates This review will discuss numerous methods of association of CNTs to nucleic acids, advances made in CNT-mediated delivery of therapeutic nucleic acids, and discuss the controversy that exists in current literature reports.