I give an overview of the recent scientific results based on observations of PAH emission
from circumstellar disks around young stars. The stellar radiation field plays a key role
in the excitation and destruction of the PAH molecules in the disk. The detection rate of
PAH emission in disks is optimal for stars of spectral type A. Around stars of similar
temperature, the disk structure determines the PAH emission strength: disks with a flared
geometry produce stronger PAH emission than flattened disks. The spectral properties of
the emission features, indicative of the chemistry of the emitting hydrocarbons, is
closely linked to the central star radiation field. The main PAH features shift to redder
wavelengths with decreasing stellar effective temperature. This trend has been interpreted
as an indication for a higher aliphatic/aromatic ratio of the hydrocarbon mixture around
cool stars with respect to hot stars. An alternative explanation may be a more significant
contribution to the infrared emission of very small grains around cooler stars.