The various transformations that Quebec society was undergoing throughout the 1980s are reflected in the dramaturgy of the period, notably in the critique of nationalist discourse, and in the writing of hitherto marginalized groups such as women, immigrants, and gays and lesbians. / The tensions within the family unit are one of the leitmotivs of Quebec theatre in the 1980s, which usually represents the mother either as a sort of monster who suffocates her children, or as a victim of the Law of the Father. When a woman decides to speak and to redefine motherhood, this dual model of the "patriarchal mother" crumbles and the universe of the family must be reconfigured. / In this thesis, we propose a semiological analysis for each of the plays of our corpus. The first chapter analyzes Addolorata, by Marco Micone. In this play, the mother's taking possession of speech not only destabilizes her family but also calls into question established structures within the Italo-Quebecois community. The second chapter examines Marie Laberge's Aurelie, ma soeur, a play which illustrates the (re)construction of the family unit around a nonbiological maternal bond. The third and final chapter studies Michel Marc Bouchard's Les Muses orphelines, in which access to speech and to the condition of mother is achieved through lies and truth. In the conclusion of this thesis, we bring together the principal characteristics of the feminine and maternal voices which are heard in the three plays, voices which are all defined by the desire, the need to affirm their subjectivity.