This GRBs Catalog (GRBCAT) records high level information of the GRBs detected since their discovery in 1967. The catalog has been created using publications that report lists of GRB detections. These are mostly papers already published in refereed journals, unpublished papers, and PhD thesis presenting lists of GRBs. GRBCAT includes also compilation of bursts that were already present in the HEASARC database system. The catalog is organized with a main table reporting general information for each GRB and additional tables linked to the main table where specific information for the flux and the region of detection are reported. Afterglow measurements are also recorded in a separate table for all bursts detected after May 11 1996. The main table for each GRB contains an entry for each satellite that reports a detection with either a flux and/or position measurement. Therefore for a given GRB there are multiple records if the GRB was detected by more than one satellite. The associated flux table contains an entry for each flux and fluence values reported in literature for a given energy band. The positional information is reported via different tables each dedicated to a specific region of detection. The region descriptions are the following : circle, annulus, box, dual, annulus intersect, irregular, and intersect. The associated afterglow table contains position, intensity and redshift measurements taken after the discovery of the GRB. There are several records associated to a given GRB/afterglow since several observatories collected data on that position. The main table and the associated tables are updated when a new GRB and/or afterglow measurements are reported. This table was ingested by the HEASARC in June 2008 based on electronic versions obtained from the author(s), who compiled the catalog in 2005. This is a service provided by NASA HEASARC .