Cystoseira sensu lato (s.l.) forests are among the most complex and productive habitats along the rocky shores of the Mediterranean Sea. These habitats provide many ecosystem services, including carbon sequestration and coastal protection, and due to their three-dimensional structure and ecological role provide shelter and trophic resources for a wide range of benthic organisms. Indeed, although being poorly studied, macrozoobenthic communities associated with Cystoseira s.l. forests are considered a key component of biodiversity in Mediterranean coastal ecosystems and can provide valuable information for assessing the ecological status of these habitats.This study aimed to characterize the composition and diversity of the macrozoobenthic assemblages associated with Cystoseira s.l. forests in Santa Maria di Castellabate Marine Protected Area (Tyrrhenian Sea, Southern Italy). Samples were collected in January 2024 using the suction-brush technique, at three stations with three replicates per station and at a depth of 6.5 m. Algal material and associated fauna were sorted and macrozoobenthos was identified, reporting its abundance, taxonomic richness, Shannon’s diversity index, and Pielou’s evenness index. A total of 6 taxa were identified. Crustacea, Polychaeta, and Mollusca were the most abundant groups. Specifically, Crustacea accounted for 62% of the total abundance, followed by Polychaeta (24%) and Mollusca (10%). The mean values of the Shannon’s diversity index and Pielou’s evenness index among samples were 1.07±0.25 and 1.37±0.32, respectively. The results showed that three-dimensional Cystoseira s.l. forests support diverse biological communities. This confirms the role of Cystoseira s.l. as habitat-former, sustaining complex communities and enhancing the resilience of coastal habitats. Their conservation is therefore essential for preserving Mediterranean marine biodiversity.