Abstract. This paper investigates Description Logics which allow transitive closure of roles to occur not only in concept inclusion axioms but also in role inclusion axioms. First, we propose a decision procedure for the description logic SHIO+, which is obtained from SHIO by adding transitive closure of roles. Next, we show that SHIO+ has the finite model property by providing a upper bound on the size of models of satisfiable SHIO+-concepts with respect to sets of concept and role inclusion axioms. Additionally, we prove that if we add number restrictions to SHI+ then the satisfiability problem is undecidable.