An extensive compilation of nearly 700 field estimates of net primary productivity of natural and agricultural ecosystems worldwide was synthesized in Germany in the 1970s and early 1980s. The literature cited dates from 1869 to 1982, with the majority of references from the 1960s and 1970s. Although the Osnabrück data set has not been updated since the 1980s, it represents a wealth of information for use in model development and validation. This data paper documents the development of this data set, its contents, and its recent availability on the Internet, both in Ecological Archives on the Ecological Society of America's web site, and in a “mirror” copy at the Oak Ridge National Laboratory Distributed Active Archive Center for Biogeochemical Dynamics. The version presented here (version 2.0) incorporates amendments suggested by data users over the past two years. Caution is advised in using these data, which necessarily include assumptions that may not be universally applicable to all study sites and records. Nevertheless, we consider these “Class III” data to be useful, even though they may not meet the “Gold Standards” which are being developed for this type of data (mainly because the documentation may be incomplete, not because the numbers themselves are of poor quality).