Electronic prescription use seems to be a predictor of pharmaceutical expenditure in which every percentage increase relates to an average annual increase of 1,027 Euros. This variable along with the prescription by active principle, and the amount of TAFEs assigned, as well as the burden of care and number of visits, are variables which help to explain more than 65% of the PE variability between physicians. Likewise, the increase in expenditures related to electronic prescriptions seems to occur at the expense of increasing number of prescriptions per patient.