Optically quiet quasars (OQQs) are compact radio-loud and X-ray-bright
active galactic nuclei with very weak optical continuum emission. Sev
eral explanations have been proposed for the inverted spectral energy
distribution (SED) of OQQs, the most likely being reddening and soft X
-ray absorption in excess of that expected from the Galaxy. We have ma
de multifrequency observations of three previously known OQQs. The The
X-ray spectra are consistent with excess absorption, although we cann
ot rule out alternative explanations. The wide range of radio and opti
cal properties in these sources suggests that, if excess absorption is
important, it arises from a physically unrelated system that intercep
ts the line of sight. We also observed 10 OQQ candidates selected from
two correlations of the ROSAT All-Sky Survey (RASS) with radio survey
s. No clear examples of new OQQs were found.