Since 1956, developments in the prison population and the flux of immigration have been dominated by the 'Algerian problem.' After the Evian agreements were signed in 1962 there was a period of 'free' and massive, immigration until 1974. Since then, the volume of legislation rivals and probably surpasses the British experience. Together they are the formal expression of the near illegality of being foreign. The day-to-day reality of this tenuous citizenship status is documented in the second half of the paper. Many of the police in the 1960' also belonged to the Service d'Action Civique, a Gaullist strong-arm association; and, since 1974, an increasing proportion of immigrants are being imprisoned. Second generation immigrants also suffer discrimination wherever there is discretion. Overall, the French tradition of being the home of political refugees looks very tarnished. (Author abstract)