Object-oriented data models are being extended with recursion to gain expressive power. this complicates the optimization problem which has to deal with recursive queries on complex objects. because unary operations invoking methods or path experssions on objects may be costly to execute, traditional heuristics for optimizing recursive queries are no longer valid. in this paper we propose a cost-based optimization method which handles objects-oriented recursive queries. in particular it is able to delay the decision of pushing selective operations through recursion until the effect of such a transformation can be measured by a cost model. the approach integrates rewriting and increases the optimization opportunities for recursive queries on objects while allowing for efficient optimization.