Cheri, P. V.P. V.CheriDey, DeblinaDeblinaDeyK, AkhilAkhilKKotal, NirmalNirmalKotalVeer, DharmDharmVeer2025-08-282025-08-282023-10-012331-842210.48550/arXiv.2310.17343https://d8.irins.org/handle/IITG2025/20119In this article, we characterize Cohen-Macaulay permutation graphs. In particular, we show that a permutation graph is Cohen-Macaulay if and only if it is well-covered and there exists a unique way of partitioning its vertex set into r disjoint maximal cliques, where r is the cardinality of a maximal independent set of the graph. We also provide some sufficient conditions for a comparability graph to be a uniquely partially orderable (UPO) graph.en-USe-Printe-Print123456789/555