[Integrins and reproduction]. Integrinas y reproducción. Integrins are glycoproteins of dimeric structure and promote the binding between the cytoplasm and the Intercellular Matrix System or ICM. Its mechanism of action is very diverse and also very complex in each case; but it is very interesting to note that its intervention in reproductive processes is of paramount interest. Integrins promote the penetration of the head of spermatozoon into the oocyte, cause the secretion of nutrient substances in the tubal mucosa and finally determine the formation of the "implantation window" in the endometrium. Further penetration of egg in the decidua and the formation of the placental trophoblast originate from the action of integrins. In certain pathologic situations as ectopic pregnancy or endometriosis, integrins play a primordial role. In the treatment of infertility and in the technology of IVF.