  Graph products of cyclic groups and Coxeter groups are two families of groups
that are defined by labeled graphs. The family of Dyer groups contains these
both families and gives us a framework to study these groups in a unified way.
This paper focuses on the growth series of a Dyer group $D$ with respect to the
standard generating set. We give a recursive formula for the growth series of
$D$ in terms of the growth series of standard parabolic subgroups. As an
application we obtain the rationality of the growth series of a Dyer group.
Furthermore, we show that the growth series of $D$ is closely related to the
Euler characteristic of $D$.
