Abstract Spiny lobsters are the main target of commercial fisheries along the coast of Brazil. Little is known about lobster egg production, making it difficult to estimate reproductive capacity. The purpose of this study was to update fecundity data on Brazilian lobsters as a subsidy for stock management and prevention of overexploitation. For the first time, fecundity equations for the two main Brazilian species of spiny lobster are proposed: Egg count = 29 552e0.0274x (; ; ) for Panulirus argus (Latreille, 1804) collected off Northeastern Brazil and the Great Amazon Reef System, and Egg count = 13 662e0.0361x (; ; ) for Panulirus laevicauda (Latreille, 1817) collected off Northeastern Brazil in 2021. Mean fecundity data for the period 1968-2021 show that fecundity levels declined over four decades, then partially recovered after the 6-month closed season was implemented in 2012, suggesting the measure has been effective at protecting lobster reproduction, allowing stocks of both species to recover between fishing seasons. Efficient management requires strict control of lobster fisheries, regular collection of reliable fishing data and investments in life cycle research.