  We derive the 3-point correlation function between two giant magnons heavy
string states and the light dilaton operator with zero momentum in the
\eta-deformed AdS_5 x S^5 valid for any J_1 and \eta in the semiclassical
limit. We show that this result satisfies a consistency relation between the
3-point correlation function and the conformal dimension of the giant magnon.
We also provide a leading finite J_1 correction explicitly.
