ABSTRACT. – The fine structure of the octopod Graneledone gonzalezi spermatozoa is described by electron microscopy. The acrosome is the longest ever found in Octopodidae. It consists of a long striated cone surrounded by a single helix, which is defined by a numerical expression. The nucleus is rod shaped and one of the largest in Octopodidae. The nuclear fossa reaches up to the fifth part of the nucleus acting as a flagellar root due to its connection with the axoneme-coarse fibres (ACF) via the centriole. Using the morphological characteristic of the sperm, the relationship of Graneledoninae within the family Octopodidae is discussed.