  We present the results of deep VLT-ISAAC Ks-band imaging of four z~1.5
flat-spectrum quasars selected from the Parkes half-Jansky flat spectrum
sample. We find that the hosts of these flat-spectrum quasars are consistent
with lying on the K-z Hubble relation for radio galaxies. This implies that the
flat-spectrum quasar hosts fall in line with the expectations from orientation
based unified schemes and also that they contain black holes of similar mass.
Moreover, the width of the Hbeta broad emission line in these objects tends to
be narrower than in their misaligned (low-frequency selected quasar)
counterparts, implying that the width of the Hbeta broad emission line depends
on source inclination, at least for radio-loud quasars, in line with previous
studies.
