Abstract. We consider the problem of automatically disproving invalid conjectures over data structures such as lists and arrays over integers, in the presence of additional hypotheses over these data structures. We investigate a simple approach based on refutational theorem proving. We assume that the data structure axioms are satisfiable and provide a template language for additional hypotheses such that satisfiability is preserved. Then disproving is done by proving that the negated conjecture follows. By means of examples we demonstrate that our template language is reasonably expressive and that our approach works well with current theorem provers (Z3, SPASS+T and Beagle).