This doctoral thesis in Linguistics is part of the field of French Discourse Analysis (FDA) and its main goal is to investigate the relationship between language, discourse and suicide. The study is based on the assumption that the act of suicide can be understood as a complex discursive phenomena that transcends merely pathological explanations. It seeks to analyze the way in which suicidal subjects construct their identities and subjectivities in/through language, especially with regard to suicide letters. The research adopts an interpretative approach, using the theoretical premises underpinning ADF to analyze the discourse of suicidal subjects. One of the key points of the analysis is the consideration of the conditions of production of the suicidal discourse. This implies understanding the socio-historical and ideological context in which the discourse is produced, recognizing that the act of suicide does not occur in a void, but is rooted in a complex network of cultural and social influences, which we can call interdiscourse. The corpus of analysis consists of letters and virtual messages left by suicidal subjects. The relationship between language, discourse and suicide is complex and multifaceted, so this research represents a contribution to a deeper understanding of this phenomena.