The article concerns the environmental study of cave 17 in Ajanta – India. The monitoring program included microclimate, air quality and biodeteriogens surveys. The monitoring campaigns have been carried out after the wet and during the dry season to show different situations. The microclimatic monitoring has highlighted a significant variability of relative humidity in the cave. The moisture content of the walls during the wet and the dry seasons is, instead, definitely steady. This result can be linked to the presence of low permeability varnishes on the mural paintings. A high presence of airborne sulphate, probably due to the works in progress for new outside cement paths, has been highlighted. By entomological study, insects which contribute to the decay of the conservation conditions of the mural paintings have been isolated. A database (GIS) sets results and data in relationship with the graphic 3D laser survey of the monument.