This article aims to study an important principle in discourse analysis, which belongs to Paul Grice, the contemporary philosopher. He believes that in addition to giving and taking information during a conversation, people also show their cooperation with each other, and so he suggests the ‘cooperative principle’ which contains some principles of subtext. Since the cooperative principle is with regards to dialogue and conversation, it can be applied to plays. This article studies the cooperative principle in Top Girls by Caryl Churchill and through this study, it shows the political and feminist approaches in this play, because these approaches are shown through language. The goal of this article is to show how Churchill was or was not successful in showing her ideological beliefs through language and cooperative principle in particular. Through this study, it will be shown how linguistics and its principles, strengthen the dramatic effects and help the dramatist to show his/her ideology.