This study compares the MODerate resolution Imaging Spectroradiometer (MODIS) total precipitable water (TPW) and ozone products with other satellite- and ground-based observations. The work involves comparisons of MODIS TPW with Geostationary Operational Environmental Satellite (GOES) TPW and independent measurements at the Atmospheric Radiation Measurement (ARM) Cloud and Radiation Testbed (CART) site. Investigation of the MODIS ozone product is conducted through continental-scale comparisons of MODIS to GOES-8 and GOES-10 ozone products. On a larger spatial scale, a global comparison is made between MODIS products and measurements from the Total Ozone Mapping Spectrometer (TOMS).