Benthic foraminifera, worldwide single-cell marine organisms, represent an important component of seabed ecosystems. Due to their sensitivity to environmental changes, they are often used as bioindicators, providing an efficient tool in toxicity studies. Among the pollutants affecting marine coastal and estuarine environments, persistent flame retardants such as polybrominated diphenyl ethers (PBDEs) are frequently found. Low-level exposure to BDE-47, a PBDE congener, is known to affect organisms development. In this framework, this study aims to assess the effects of BDE-47 exposure on benthic foraminifera from coastal marine environments. Foraminifera specimens belonging to the symbiont-bearing Peneroplidae family were sampled and exposed to two different BDE-47 concentrations from T0 up to 48 h (T48). Vitality indicators such as changes in pseudopodial activity, movement, reproduction, loss of symbiont algae, and eventual death were monitored during the experiment. Exposure to BDE-47 induced alterations in pseudopodial activity, movement, reproduction, and symbiont retention, with progressive loss of vitality and eventual mortality at increasing exposure levels, highlighting the sensitivity of this species to BDE-47 exposure. These findings suggest the harmful repercussions of PBDE pollution on marine coastal ecosystems, affecting benthic organisms and potentially contributing to biomagnification processes within the food web, with possible implications for human health.