This progress report provides an overview on recent advances in bioapplication of carbon nanotubes including the chemical modification of carbon nanotubes targeting specifically their covalent and noncovalent conjugations with a variety of biological and bioactive species (proteins and peptides DNAs/RNAs and carbohydrates). Furthermore the significant recent development and progress in the use of carbon nanotubes for biosensors drug and other delivery systems bioimaging etc. and in the understanding of in vivo biodistribution and toxicity of carbon nanotubes are reported.