Abstract. C. Faith and J. Cozzens have shown that a ring, whose right proper cyclic modules are injective, is either semisimple or a simple, right semihereditary, right Ore K-domain. They have posed a question as to whether such a ring is right noetherian. In this paper, an affirmative answer is given to that question. Moreover, necessary and sufficient conditions are given as to when a right PCI ring is left PCI.In [1], Faith and Cozzens proved that a ring R whose proper right cyclic modules are injective must be either semisimple or a simple, right semihereditary, right Ore F-domain. They noted that all the known examples of such rings are right noetherian and posed the question whether every ring with this property is noetherian. We will answer this question in the affirmative. More clearly, we will show: Theorem 1. Let R be a right PCI ring, then either