Place beans in a large saucepan and cover with water. Bring to a boil; cook, uncovered, for 8-10 minutes or until crisp-tender; drain.
In a large skillet, saute onion in butter for 3 minutes or until crisp tender. Add zucchini; saute for 4 minutes or until vegetables are tender. Stir in the bacon, beans, salt and pepper; heat through.