We study the fully compressed pattern matching problem (FCPM problem): Given [Formula: see text] and [Formula: see text] which are descriptions of text T and pattern P respectively, find the occurrences of P in Twithout decompressing[Formula: see text]or[Formula: see text]. This problem is rather challenging since patterns are also given in a compressed form. In this paper we present an FCPM algorithm for simple collage systems. Collage systems are a general framework representing various kinds of dictionary-based compressions in a uniform way, and simple collage systems are a subclass that includes LZW and LZ78 compressions. Collage systems are of the form [Formula: see text], where [Formula: see text] is a dictionary and [Formula: see text] is a sequence of variables from [Formula: see text]. Our FCPM algorithm performs in [Formula: see text] time, where [Formula: see text] and [Formula: see text]. This is faster than the previous best result of O(m 2 n 2 ) time.