This document presents an atlas of length-weight relationships of 93 different fish and crustacean species from the North Sea and the North-East Atlantic. The length and weight data are based on individual measurements from German fisheries research surveys and German commercial fishing vessels, conducted by members of the Thünen Institute of Sea Fisheries (and its predecessor institution). With the first survey carried out in 1959 and the latest data entered in 2011, the compilation is based on a comprehensive data set collected over more than 50 years. An extensive overview on length weight relationships is given by geographical area, season and partly by sex, of the described species. Users, who would prefer using relationships based on other time series or subunits, which are not represented in the Atlas, are invited to contact the author for the respective subsets of data.