This paper is a catalog of Seyfert 2 galaxies observed in the 2-10 keV band (339 flux entries). In total, it contains data on 150 objects; for 76 objects, a positive detection is reported, while for the remaining sources, 2 σ upper limits to the X-ray emission are given. Most of the data have been collected from the literature over a period starting from 1974 up to the middle of 1995. Accurate searches of literature and databases were performed for all objects, and frequently spectral fits were reevaluated in order to make the data in the catalog uniform and complete. Some unpublished data are also included. For six objects, EXOSAT/ME date have been extracted from the satellite database and analyzed; the 13 fluxes obtained have been added to the present catalog. The compilation of hard X-ray data has been complemented with data in the soft (0.1-3 keV) X-ray band, as well as in ultraviolet (1450 A), optical (5500 A), infrared (3.5, 12, 25, 60, 100 micron), and radio (6 cm) bands. Fluxes of the [O II] λ5007 and Hβ emission lines as well as the Balmer decrement Hα/Hβ, and axial ratio a/b are also given. The present database is meant to be a useful tool for the study of the Seyfert 2 phenomenon in its various aspects.