This study concerns the migration flows by age groups of the Outaouais population for the period 1971-1981. The method used is a principal components analysis applied on net migration data, for the 103 municipalities of the region, using a KHI transformation. The results identify clearly the main migration behaviors which have affected the spatial redistribution of the population between 1971 and 1981 in the Outaouais region. They also show the key role played by some age categories, especially those who have a greater probability of household composition change. Finally, it is shown that the demographic evolution of the municipalities forming the Communauté regionale de l'Outaouais is quite different from that of other municipalities and may lead to some more severe disparities.