For Banach spaces X and Y , we establish a natural bijection between preduals of Y and preduals of L(X, Y ) that respect the right L(X)module structure. If X is reflexive, it follows that there is a unique predual making L(X) into a dual Banach algebra. This removes the condition that X have the approximation property in a result of Daws.We further establish a natural bijection between projections that complement Y in its bidual and projections that complement L(X, Y ) in its bidual as a right L(X)-module. It follows that Y is complemented in its bidual if and only if L(X, Y ) is (either as a module or as a Banach space).Our results are new even in the well-studied case of isometric preduals.