Thanh Tâm Tuyền (1936–2006) was a great writer of South Vietnamese literature in the 1954–1975 period. His works are extremely diverse in genres, having made remarkable contributions to the modernization of Vietnamese literature in many aspects. However, in general, critics have drawn more attention to Thanh Tâm Tuyền’s unique innovations in poetry rather than his prose fictions whose achievements are also very notable in fact. On the basis of reading Thanh Tâm Tuyền’s short stories and novels from the perspective of narratology, poetics and existentialism, the paper contributes to analyzing, explicating and interpreting his narrative art. Specifically, we argue that freedom is an important core in Thanh Tâm Tuyền’s fictions and even in his entire writing career. Firstly, Thanh Tâm Tuyền had a special narrative style, with which he did not create narrative worlds, situations and characters as the mediums of his ideological statements and conclusions, but very discrete ones, sometimes full of structural flaws and incompletedness, which, however, can stimulate his readers to freely figure out and contemplate various metaphysical problems in their own way. Second, the article presents an understanding of the nature of life suggested by Thanh Tâm Tuyền’s prose fictions, which is also related to the concept of freedom: his short stories and novels, to some extent, indicate human suffering of living without freedom, with the term understood as being honest with oneself to escape from illusions and invisible impositions.