Let Lambda be a Z-graded artin algebra. It is proved that the category of graded A-modules is pure-semisimple if and only if there are only finitely many nonisomorphic indecomposable finitely generated graded Lambda-modules. As a consequence of this result together with a known result of Gordon and Green (which states that Lambda is of finite representation type if and only if there are only finitely many non-isomorphic indecomposable finitely generated graded Lambda-modules), we see that the category of all Lambda-modules is pure-semisimple if and only if the category of all graded Lambda-modules is so.