The aging process we are witnessing in the majority of developed countries is raising financial sustainability problems in the pay-as-you-go pension system. The reforms designed to re-establish the financial equilibrium of pension systems may put one of the most important objectives of these systems at risk: to reduce the poverty rate among the elderly. This paper studies the effects that the reforms implemented in the Spanish pension system would have on the poverty rate of the retired population. The two main novelties presented are the following. First, the collective under study is focused on the most vulnerable workers. Second, the effects of the reforms are studied taking into account the labour market situation of the individuals in the years prior to retirement.