P.Collet, S.Martinez, B.Schmitt. The Pianigiani-Yorke Measure for Topological Markov Chains. (67K, ps, gzipped, uuencoded) ABSTRACT. We prove the existence of a Pianigiani-Yorke measure for a Markovian factor of a topological Markov chain. This measure induces a Gibbs measure in the limit set. The proof uses the contraction properties of the Ruelle - Perron - Frobenius operator.