Suicide mortality rates decreased in France from 1996 to1999, and a difference was observed between the 11 regions which have implemented suicide prevention programmes (Programmes régionaux de santé (PRS)) and the 11 others which have not launched PRS of this kind. The former regions showed a sharper decrease in their suicide mortality rates than the latter. In the present study, the explanatory factors underlying these differential regional trends were examined using an ecological model. Principal component analysis (PCA) and multiple regression procedures provided consistent findings in terms of the main factors associated with the male and female mortality rates, which were found to be unemployment problems and economic inequalities, respectively. However, these factors do not explain the differential regional trends. The suicide mortality rates were negatively correlated with regional lithium prescription rates in the case of males, whereas alcohol withdrawal drug prescription rates were positively correlated in the case of females. It is still difficult to conclude whether the PRS definitely had positive effects. However, no single variable alone can account for all the trends in the suicide rates