PKSCAT90 consists of radio and optical data for 8264 radio sources. It covers essentially all the sky south of declination +27 degrees but largely excludes the Galactic Plane and the Magellanic Cloud regions. The latter zones have been the subject of other, specialist surveys. A few data errors in Version 1.00 have been corrected in the present edition. This version of the Parkes Radio source Catalogue entitled "PKSCAT90 Version 1.01" is intended for use on IBM PC-type machines. Note by A. Wright: Users should note that PKSCAT90 was produced at a time when relational databases were in their infancy. In the future we anticipate making the individual data sources available separately --- through such search systems as SIMBAD --- rather than in an "omnibus" catalogue like PKSCAT90. For both the Northern and Southern hemisphere, superior and deeper finding surveys now exist: the 87GB Catalog in the North, (Condon et al., catalog <VIII/14>) and the PMN catalogues (Griffith and Wright, catalog <VIII/38>) in the South.