'A Cow of Sin' is an Akkadian incantation for a woman in childbirth. It contains a small mythological narrative (about 20 lines) about the moongod and his beloved cow, Geme-Sin. Sin falls in love with his cow and impregantes her. When at the end of her pregnancy the birth-pangs begin, Sin hears her cries in heaven. Two helping spirits descend to earth and perform a ritual to ease the birth. The incantation ends with a supplication: may this woman give birth as easily as Geme-Sin. Veldhuis presents the various versions of the text and offers a literary analysis which takes into account the poetic and pragmatic aspects of the incantation. This study is meant both for the Assyriologist and for anyone interested in Akkadian literature.