Wettability studies of liquids inside nanometre scale channels commenced shortly after the discovery of carbon nanotubes in the early 1990s. Since then the field has progressively expanded to other kinds of nanotubes and nanochannels as they have become available. This paper offers a critical review of wettability studies inside and outside nanotubes and nanochannels published in the last three years (2008-2010). The review focuses in particular on three areas, the wetting behaviour of water and aqueous fluids inside nanotubes, the wetting of polymers inside and outside nanotubes and the wetting of nanotube arrays or forests. The authors believe that there is scope for further growth of this research area as there are a number of interesting topics that deserve further investigation.