The Authors carried out a survey in 25 gyms in the city of Pescara during the period May-July '93 to evaluate their building characteristics, management and organization and to assess microclimate and microbial contamination of the indoor environment. Most of the gyms were not in conformity with the current regulatory issues and because of the lack of basic requirements, e.g. climatisation, the microclimate, expressed as comfort indexes, was by far inadequate. The microbiological findings clearly demonstrated poor hygienic conditions particularly in dressing-rooms and toilets. The Authors, given the inadequacy of most of the gyms examined, point out the need of specific mandatory regulations to assure acceptable levels of indoor climate, hygiene and safety.