In this article, we describe a facile and effective method for the modification of multiwall carbon nanotubes with molecular anchor molecules using supercritical fluids (SCFs). Through choice of deposition conditions, the degree of loading in these nanotube-anchor structures can be controlled to achieve sub-monolayer, monolayer, or greater-than-monolayer coverage. This level of control represents a potential advantage of SCFs over liquid solvents for anchor deposition. Employment of the described technique is expected to enable the direct addition of desired chemical functionality to many carbon nanotube structures for a variety of applications.