The incomplete combustion of fossil fuels is one of the more important contributions of organic compounds to the atmosphere. Most of them can be detected in the aerosol and a number of these are known to be carcinogenic and mutagenic. For this reason, it is necessary to control their emission for environmental protection. Multivariate techniques were applied to the results obtained after a previous development of analytical methodologies, including sampling and determination by gas chromatography-mass spectrometry of the ahphatics and polynuclear aromatic hydrocarbons compounds in airborne particulate matter. Both chemical parameters [e.g. biogenic and anthropogenic alkanes, carbon predominance index (CPI), unresolved complex mixture (UCM) and aromatic hydrocarbons] and meteorological (temperatures, rainfall and daily sunlight period) parameters were determined weekly during the period January 1989-December 1990 at two sampling sites located in the centre of Madrid (a highly polluted area). Another site was located in a residential area and another one far from any polluting source. Correlation studies, factor analysis and cluster analysis were applied to the raw and transformed data, showing different patterns related to the anthropogenic activity along the year, that can be distinguished by means of these studies with the organic pollutant values and the meteorological conditions during sampling.