Path traversals have been recognized as one of the strengths of object-oriented query processing as object retrieval can be carried out through pointer navigation. Apart from path traversals, explicit join between objects is sometimes necessary in Object-Oriented Databases (OODB), due to the absence of pointer connections or the need for value matching between objects. Like in Relational Databases (RDBMS), join operations are still, if not more, expensive in OODB. In this paper, we propose an optimization strategy for object-oriented collection join queries through the use of path traversals. Our performance evaluation shows that optimization of collection join queries gains some performance benefits.