The aim of this paper is to examine the view of responsibility A.K. Sen and J.E. Roemer support via their theories (Roemer’s Equality of Opportunity principle and Sen’s capability approach). The comparative analysis between these approaches is motivated by Roemer’s atypical opinion about Sen’s capability approach. A brief overview of the modern theories of justice is necessary to understand the issues raised by the treatment of responsibility and to realize properly in which way Roemer’s position is questionable. These statements lead to a thorough comparison between both theories.