Summary: Length–weight relationships were observed for six elasmobranch species from the Adriatic Sea. Between 2006 and 2019, data on weight and total length were collected for three shark species Alopias vulpinus, Mustelus mustelus, Mustelus punctulatus; and data on weight and disk width were collected for three batoid species Aetomylaeus bovinus, Myliobatis aquila, Pteroplatytrygon violacea. Data collection comes from monthly observations as part of a monitoring program targeting specifically bycatch on pelagic pair trawlers involved in anchovy and sardine fishing. This fishery operates using pelagic trawls with a minimum mesh size opening of 20 mm. All elasmobranchs were measured to the nearest cm using a measuring board and weighed to the nearest gram using an electronic scale or a dynamometer for the largest specimens. A linear regression analysis performed on log‐transformed data was used to estimate intercept and slope, and to describe the length–weight relationship for each species. [ABSTRACT FROM AUTHOR]