Spain had one of the lowest breast cancer mortality (BCM) rates in Europe a decade ago but this is no longer the case. A study of the trends of breast cancer mortality in Spain during the last 30 years, and an analysis, at the ecological level, of the current and past dietary patterns associated with breast cancer mortality have been conducted. Age standardized rates and standardized mortality rates (SMR) for this period were calculated. Dietary information about 20 different groups of foods for the 50 Spanish provinces was obtained from two National Household Budget and Expenditure Surveys, conducted in 1964-1965 and 1980-1981. Simple correlation coefficients were calculated, and multiple regression (dependent variables: BCM and breast cancer SMR) with a stepwise procedure was performed. Trends of breast cancer mortality in Spain for the last 35 years indicated a 100% increase in the 35-64 years group. Results indicate important changes in food consumption patterns in Spain, departure from the traditional Spanish diet, and the association of breast cancer mortality with past (15 years period) consumption of beef and total meat and the current consumption of vegetable oils, among other features of interest. Past consumption of meat and particularly beef meat seems to be associated with current breast cancer mortality rates in Spain. However, results at ecological level need to be confirmed in individuals.