  We compute euclidean coordinate space correlation functions in a holographic
model of QCD. We concentrate, in particular, on channels that are related to
the U(1)_A problem, the flavor-singlet axialvector, pseudoscalar meson, and
pseudoscalar glueball (topological charge) correlator. We find that even a very
simple holographic model defined on a slice of AdS_5 provides a qualitatively
correct description of QCD correlation functions. We study the role of anomaly
terms, and show that both euclidean positivity and low energy theorems based on
the axial anomaly relation are correctly implemented. We compare the results
with expectations from an instanton model of the QCD vacuum.
