The influence of carbon nanotube (CNT) curvature and graphitization, pyrene derivative steric hindrance and pyrene diffusion in solution on the adsorption on CNTs of three water soluble pyrene derivatives was investigated. This study demonstrates that the diffusion effect can easily be eliminated by magnetic stirring. It also proves that more the CNT surface is flat (low curvature) and well graphitized, easier the adsorption is. In the second part of the work, the polyaromatic derivatives adsorption on the CNT surface is used to determine the specific surface of the samples with the help of BET and Langmuir equation. It is shown that the specific surface obtained corresponds to what is known for the CNT, taking into account their treatments (freeze-drying, high temperature evacuation, etc.).