Tetrabromobisphenol A (TBBPA) is a brominated flame retardant with endocrine-disrupting properties that threatens aquatic ecosystems. This study investigated TBBPA toxicity in the freshwater snail Lymnaea stagnalis across multiple life stages at concentrations of 3.5–100 µg/L (chemical analysis revealed >80% reduction by day 3). Endpoints included mortality, feeding, behavior (withdrawal-induced recovery latency, WIRL), reproduction, and embryonic developmental toxicity. Additionally, carry-over effects from exposed parents on unexposed F1- and F2-generations were examined. Adults were exposed for up to 28 days, juveniles and embryos for 14 days. Mortality remained low (<10%). WIRL increased in adults and juveniles at concentrations ≥ 30 µg/L. Reproduction was impaired with an EC₅₀ of 31.8 µg/L. Directly exposed embryos exhibited malformations and delayed hatching (EC₅₀ = 20.2 µg/L). F1- embryos from exposed parents showed similar abnormalities at slightly lower sensitivity. The unexposed F1 generation’s reproductive output was twice as sensitive as their exposed parents. Neither F1 nor F2 recovered from these effects, as reduced shell size persisted. These findings demonstrate that TBBPA can also cause population-relevant long-term effects in snails like L. stagnalis and highlights the need for multi-generational testing in chemical risk assessment.