Recent studies from our laboratories have clearly shown the utility of the carbon nanotubes (CNTs) in biomedical applications. Therefore, the behaviour of CNTs following in vivo administration is of high interest. In this paper, we summarise some of our previously published results towards the assessment of the health impact of CNTs. We will initially describe the in vivo distribution of radiolabelled multi-walled CNTs (MWNTs) once they reach systemic circulation using micro Single Photon Emission Tomography (microSPECT) imaging and scintillation counting. Our conclusions on the effect of CNT degree of functionalisation on the tissue accumulation will also be described. Finally, our proposed mechanism of CNT elimination from the body through the kidney glomerular filtration barrier will be shown. Overall, through this overview of our recent studies we offer a summary of why we believe the development of functionalised carbon nanotubes can be further explored since it increasingly offers biocompatible material with lack of toxic responses. © 2011 Inderscience Enterprises Ltd.