G. Bruns (1995) has proposed a version of value-passing CCS in which an agent language, based on that proposed by Milner, is augmented with a rich data language. The data language can be used to describe sets, tuples and sequences etc. constructed from integer, Boolean and string constants. Z is a widely used formal specification language in which sets, tuples and sequences can be described, but also additional constructs such as free types and bindings. In addition, Z has a rich structuring mechanism-its schema calculus. Z is frequently used to specify the operations of a system on its state, and has a refinement calculus and formal semantics. This article introduces ZCCS, a version of value-passing CCS in which the data language used to describe the action/agent parameters and conditions is Z. We introduce the style and syntax of ZCCS and illuminate this with a small example. In addition, we present an operational semantics for ZCCS.