In this paper evidence of a spin glass behaviour in FeSbO 4 rutile from susceptibility and hysteresis loop measurements are presented. The spin glass transition has as a precursor effect a strong deviation of the Curie-Weiss law at T\leq20 T_{g} which indicates that strong antiferromagnetic spin correlations develop. It is argued that antisite Fe-Sb atomic ordering makes possible that nearest neighbours interactions compete with higher order magnetic interactions.