The objective of this research was to study the effect of different levels of phosphate fertilizer on the sunflower (Helianthus annuus L.) seed quality. The experiment was carried out in a dark red Latosoil Sandy phase, in Paraguaçu Paulista City, São Paulo State. The treatments were constituted by 8 levels of P2O5 (0, 30, 60, 90, 120, 150, 180, and 210kg/ha of P2O5), it was used a completely randomized design with four replications. The characteristics evaluated were: germination %, accelerated aging test, first germination count, primary root and hipocotyl lenght, seed dimensions (lenght, width and thickness), speed of emergence, 100 seed weight and hipocotyl dry matter. It was observed that there was a signíficative effect of the P2O5 dosis used on the lenght of the primary root, hipocotyl and seed lenght. However, there was no significant effect on the germination percentage, accelerated agind test, first germination count, seed width and thickness and, 100 seed weight.