This paper is the fourth part of the series devoted to the soil oribatid fauna of Sao Paulo State (Brazil). Six new species and two new subspecies are described and seven previously known species are recorded from a new small collection of oribatid mites obtained from several localities of this state. The new species are: Archiphthiracarus sudamericanus n.sp., Hoplophorella cochlearia n.sp., Hermannobates scoparius n.sp., Xenillus imitator n.sp., Dolicheremaeus brasilianus n.sp. and Pseudotocepheur pauliensis n.sp., and the new subspecies: Brasiliotritia dlouhyorum sanctipauli n.ssp. and Rhysotritia ardua neotropicalis n.ssp.