This analysis on Portuguese mortality, between 1950 and 2005, examine two different perspectives about mortality evolution: the idea of concentrationrectangularization and the proposal of the shifting mortality. In Portugal, the increase in life expectancy is associated with the decrease of the dispersion, if all deaths are considered; but, on the other hand, there is stability in the dispersion, if the mortality before 10 years old is excluded.
The death causes effect in the mortality dispersion is also examined by means of a cause elimination life tables, express the diversity of consequences in age mortality distribution draw from each death cause.

keywords: mortality, compression, shifting, death causes.