This study set out to determine the possible influence of variations in atmospheric pressure on mortality in the Madrid Autonomous Region (MAR), taking into account the possible confounding effect of other atmospheric variables. The study was based on daily mortality data from the MAR Revenue and Excise Authority, meteorological data from Getafe Observatory and air pollution data from the Madrid Municipal Automatic Air Pollution Monitoring Grid. A time-series analysis was performed, using Box-Jenkins modelling and controlling for the respective confounding variables. Furthermore, the different variables studied (pressure, temperature, pollutants, etc.) were used to produce a multivariate model of the different causes of mortality. A significant association was found between anticyclonic trend and mortality with circulatory causes in the medium-long term and anticyclonic trend and mortality with respiratory causes in the long term.