This chapter provides data on age at puberty, duration of sexual activity, frequency of spawning, period of spawning, and zones of spawning grounds. Previous data as well as recent information are reported, mainly for the Atlantic population in France. When available, other data have also been mentioned, particularly from the River Guadalquivir (Sp) and the Elbe/Eider Rivers (D). Puberty was reached between 13 and 15 years for males and 19 and 22 years for females. Corresponding length (TL) was 140–145 cm for males and 185 cm for females. Duration of sexual activity was probably in the range of 6–10 years for males and 17–22 years for females. Frequency of spawning is mostly underdocumented. The main spawning season is May–June in the Garonne basin. Some characteristics varied with latitude, e.g., age at puberty, onset of reproduction migration. Characteristics of puberty and sexual cycles in farmed sturgeon are given, including the few available data on A. sturio.