A version of the Erdös-Rado theorem on partitions of the unordered ntuples from uncountable sets is proved, without using the axiom of choice. The case with exponent 1 is just the Sierpinski-Hartogs’ result that א(α) ≤ 2 2α . The liberal use made by Erdös and Rado in [2] of the cardinal arithmetic versions of the axiom of choice enables them to give their result a particularly simple expression...