This study examines how education and employment situation contribute to the association between a classification of occupational class based on skill assets and mortality from different causes of death. Data were obtained by linking records from the 1996 population census for Spanish men aged 35-64 residing in Madrid with 1996 and 1997 mortality records. The risk of mortality was higher in skilled, semi-skilled and unskilled workers than in higher and lower managerial and professional workers. Adjusting for educational level substantially decreased the magnitude of the gradient. The decrease in the gradient after adjusting for employment situation was much smaller. Except in the case of mortality from respiratory diseases, the mortality gradient disappeared after adjusting for both variables. These results show that education and, to a much lesser degree, employment situation explain part of the social gradient observed in mortality from all causes and from broad causes of death, except from respiratory diseases.