This paper describes the observations and data reduction techniques forthe version 2.0 images and catalog of the Near-Infrared Camera andMulti-Object Spectrometer Ultra Deep Field (NICMOS UDF) Treasuryprogram. All sources discussed in this paper are based on detections inthe combined NICMOS F110W and F160W bands only. The NICMOS images aredrizzled to 0.09" pixel-1 and aligned to the Advanced Camerafor Surveys UDF F850LP image, which was rebinned to the same pixelscale. These form the NICMOS version 2.0 UDF images. The catalog sourcesare chosen with a conservative detection limit to avoid the inclusion ofnumerous spurious sources. The catalog contains 1293 objects in the144''×144'' NICMOS subfield of the UDF. The5 σ signal-to-noise ratio level is an average 0.6" diameteraperture AB magnitude of 27.7 at 1.1 and 1.6 μm. The catalog sources,listed in order of right ascension, satisfy a minimum signal-to-noiseratio criterion of 1.4 σ in at least seven contiguous pixels ofthe combined F110W and F160W image.