This report presents the conclusions reached and recommendations made by the members of the WHO Study Group on Tobacco Product Regulation at its fifth meeting, during which it reviewed two background papers specially commissioned for the meeting and which dealt, respectively, with the following two themes. 1. Devices designed for the purpose of nicotine delivery to the respiratory system in which tobacco is not necessary for their operation. 2. Setting regulatory limits for carcinogens in smokeless tobacco. The Study Group's recommendations in relation to each theme are set out at the end of the section dealing with that theme; its overall recommendations are summarized in section 4.