Abstract. The deployment of KR formalisms to the Web has created the need for formalisms that combine heterogeneous knowledge bases. Nonmonotonic dl-programs provide a loose integration of Description Logic (DL) ontologies and Logic Programming (LP) rules with negation, where a rule engine can query an ontology with a native DL reasoner. However, even for tractable dl-programs, the overhead of an external DL reasoner might be considerable. To remedy this, we consider Datalog-rewritable DL ontologies, i.e., ones that can be rewritten to Datalog programs, such that dl-programs can be reduced to Datalog