Preheat oven to 350°F.
Wash the rhubarb and trim the stalks.
Cut into 1 1/2-inch lengths.
Peel the oranges, making sure all the pith is removed.
Cut into thin rounds and remove all pips.
Layer the fruit in a baking dish and sprinkle with sugar.
Add water and bake at until the rhubarb is tender.
Serve hot or cold.