The paper examines the structural and organisational problems of social insurance systems in Brazil and the Argentine in order to illuminate current debates about pension ‘reform’. Much of the present discussion depicts social insurance ‘crisis’ as a modern phenomenon. Similarly, preoccupations about the macroeconomic objectives of reform - profitable pension funds as an adjunct to capital market deepening, about sustainability - the financial viability of systems, and about equity and coverage, are often assumed to be peculiar to the late twentieth century. The papers stresses the generational (or cyclical) nature of crises that have plagued social insurance regimes in both countries. It also identifies what may be learnt from differences, as well as similarities, between the two systems - not least the relatively larger historic role the private sector and earlier substantive provision for rural workers in Brazil. Following an appraisal of different ‘models’ (individual ‘capitalised’ accounts versus pay-as-you-go schemes and monopolistic state systems versus pluralistic/competitive arrangements), the paper concludes with an evaluation of the administrative and financial stability of current schemes.