The MM5-CMAQ modelling system (PSU / NCAR and EPA/Models-3) has been used to provide air quality forecasting information over the Iberian Peninsula in operational mode through INTERNET. The system is set up by using HTML/CGI software languages and provides full access to air quality information by an INTERNET user. The user has complete access to all modelled species at any location and any time of the modelling period. We have used a COMPAQ/XP1000 workstation and a LINUX-PC for running both models . The script takes 48 CPU-hours to run and provides forecasts every two days however the user has always access to air quality forecasts in operational mode.