The WISE 3-Band Cryo Source Working Database (WDB) contains positions and photometry in the 3.4, 4.6 and 12 μm bands for 261,418,479 sources extracted from observations made during the WISE 3-Band Cryo survey phase, 6 August 2010 through 29 September 2010. WISE scanned approximately 30% of the sky during this period when the telescope and focal planes operated at a slightly higher temperature, but were still cooled by solid hydrogen in the inner cryogen tank. CAUTION: The 3-Band Cryo Source WDB is not a well-vetted, reliable list of infrared sources like the WISE All-Sky Release Source Catalog. The WDB contains both detections of real astronomical objects, as well as spurious detections of image artifacts, noise excursions, transient events such as cosmic rays, satellite trails and hot pixels. The WDB also contains redundant extractions of objects that fall in the overlap region between the 3-Band Cryo Atlas Tiles. The WISE 3-Band Cryo Source WDB is best used as a resource to learn more about objects that are found in the All-Sky Release Source Catalog. The 3-Band Cryo observations offer a second, independent epoch of measurement for objects in 30% of the sky, so can be used to test for object motion, flux variability and reliability in the case of very faint sources. 3-Band Cryo WDB entries have been cross-correlated with the All-Sky Catalog and associated Catalog source information is provided in the 3-Band Cryo WDB records.