The abuse of all types of substance to improve sport performance and physical fitness has spread to regularly gym users. The aim of this study was to evaluate the intake of nutritional and dietary supplements in a group of 415 individuals (260 males and 155 females) from 4 gyms in Seville (Spain). The users completed a previously designed questionnaire whose content validity had been tested in a pilot study. Out of the total sample, 56.14% had consumed a supplement at some time. Among these, the objective was improvement of physical appearance in 57.16%, health care in 16.7%, and sports performance enhancement in 13.2%. The profile of the supplement consumer is a young man who has performed activities in gyms for some time, goes to the gym for several hours a week and is on some type of diet. The percentage of nutritional supplement users (56%) is within values reported in other studies. The five supplements most frequently consumed by these individuals were (in decreasing order): proteins (28%), L-carnitine (18.6%), sport drinks (18.3%), creatine (17.1%) and vitamin complex (17.1%).