Common Agricultural Policy (CAP) direct aids are playing an essential role in supporting the income of many European farmers. This situation, the result of political choices made during successive reforms of the policy since 1992, raises the question of the appropriateness of the CAP as a means of supporting agricultural income. After a brief review of the contribution of direct payments to farm income in different European member states, we examine the effectiveness of decoupled direct aids, which constitute the bulk of direct payments, in supporting farm income. We raise the question of the legitimacy of the CAP to support farm income given that the measurement of the latter is a complex issue and that many authors consider that the CAP’s decoupled payments have no real justification.