  We discuss the scalar propagator on generic AdS_{d+1} x S^{d'+1} backgrounds.
For the conformally flat situations and masses corresponding to Weyl invariant
actions the propagator is powerlike in the sum of the chordal distances with
respect to AdS_{d+1} and S^{d'+1}. In all other cases the propagator depends on
both chordal distances separately. We discuss the KK mode summation to
construct the propagator in brief. For AdS_5 x S^5 we relate our propagator to
the expression in the BMN plane wave limit and find a geometric interpretation
of the variables occurring in the known explicit construction on the plane
wave.
