This essay examines Kafka’s use of the epistolary genre by discussing three examples (a letter to his friend Oskar Pollak, one other to Felice Bauer and the famous Letter to his Father), which have very different recipients and belong to three distant moments in his writing production. Nevertheless, they all demonstrate as a common link the vanishing of the boundaries between literature and epistolary expression. As for his diaristic production, the autobiographical form of letter turns out to be only a way to present the author behind a literary mask through the infinite kaleidoscope of refractions which is allowed by his implicit dialogue between sender und recipient.