We establish identities or estimates for the Hausdorff measure of noncompactness of operators from some generalized mixed norm spaces into any of the spaces $c_0$, $c$, $\ell_1$, and $[\ell_1,\ell_\infty]^{<m(\mu)>}$. Furthermore we give necessary and sufficient conditions for the operators in these cases to be compact. Our results are complementary to those in [1, 3, 13].