This study investigates the subgenre of the birthday poem within Breyten Breytenbach’s poetical oeuvre. Throughout the now half a century of his poetic production the writer has repeatedly written poems for himself on his birthday on 16 September of each new year (as well as a smaller number to his wife and close friends) The writing of birthday poems becomes a ritualist poetical act throughout the poet’s life and poetical oeuvre, one that has served many purposes over the years of Breytenbach’s increasingly nomadic existence. This study’s scope spans fifty years of poetical output, starting with the poet’s debut anthology, Die ysterkoei moet sweet (1964), including all the anthologies up to the publication of vyf-en-veertig skemeraandsange uit die eenbeendanser se werkruimte (2014). A small literary history is offered at the outset of the tradition of the birthday poem, based in classical Roman times (Argetsinger,K 1992) and following through to modern times. After describing the reasons for the sometimes challenging task of identifying birthday poems (unmarked by dates, having to rely on inference deduced from the content, and the like), the poems are analyzed with a particular focus on their nature and function within the larger context of the poet’s oeuvre. The research is organized according to the separate phases traceable in Breyten Breytenbach’s oeuvre (Van Vuuren 2011: 46–56), describing the steadily shifting themes and motifs of the subgenre throughout each of the four phases (pre-prison, prison, post-prison and late work phases). It was found that the birthday poems cohere as a subgenre within the oeuvre. Breytenbach’s birthday poems have a distinctive character and certain identifiable qualities (ritualistic characteristics such as reflection on the self within the present, reflection on time past, evaluating the situation and self on the particular birthday. Placed against the specific context in which the poet finds himself, with a poetical and autobiographical way forward implied in the given milieu and context, psychological insights are utilized where applicable, especially in the prison birthday poems and the late work birthday poems. A remarkable new insight gained through this study is the nature of he “reminiscence bump” (Janssen, Haque 2014) which older people experience, and is identified also in Breytenbach’s late work birthday poems. This adds to and refines the understanding of the nature of late work in Breytenbach’s poetical oeuvre. A final insight gained from the research is that description and comprehension of this smaller corpus of birthday poems (roughly thirty identified at present) may also be used as an entry into understanding of the nature of the poet’s large oeuvre (comprising twenty collections of poetry, containing around 1,600 poems between 1964 and 2014), as they represent each stage of development in Breyten Breytenbach’s oeuvre.