This paper proposes an estimation of some 20th century demographic indicators for the Republic of Vietnam : age and sex specific population estimates, vital rates, life expectancy at birth, total fertility indice (If), and net migration rates from 1909 through 1989. It takes its sources in French colonial archives and recent censuses, surveys and other research results. The reconstitution has been done stepwise using an inverse projection method. Each step has been specified, considering particularly the data it uses. Special attention has been paid to the choice of the model life table family. The reconstitution shows close fits to the 1979 and (by construction) 1989 census results. It majors Hirschman's et al. (1995) war mortality estimates and Merli's (1997) net out-migration estimates (whose age schedules have been adopted). It lowers recent Vietnamese life expectancy estimates, and majors Gourou's (1936) pre-war vital rates. The most unexpected result is the important mid-century fertility decline (1934-1954), that shows up in all scenarios.