  We present H-band VLT/NACO polarized light images of the Herbig Ae/Be star
HD169142 probing its protoplanetary disk as close as ~0.1" to the star. Our
images trace the face-on disk out to ~1.7" (~250 AU) and reveal distinct
sub-structures for the first time: 1) the inner disk (<20 AU) appears to be
depleted in scattering dust grains; 2) an unresolved disk rim is imaged at ~25
AU; 3) an annular gap extends from ~40 - 70 AU; 4) local brightness asymmetries
are found on opposite sides of the annular gap. We discuss different
explanations for the observed morphology among which ongoing planet formation
is a tempting - but yet to be proven - one. Outside of ~85 AU the surface
brightness drops off roughly r^{-3.3}, but describing the disk regions between
85-120 AU / 120-250 AU separately with power-laws r^{-2.6} / r^{-3.9} provides
a better fit hinting towards another discontinuity in the disk surface. The
flux ratio between the disk integrated polarized light and the central star is
~4.1 * 10^{-3}. Finally, combining our results with those from the literature,
~40% of the scattered light in the H-band appears to be polarized. Our results
emphasize that HD169142 is an interesting system for future planet formation or
disk evolution studies.
