ABSTRACT . – Despite their diffusion along the Mediterranean coasts, recent shore-based dead mollusc assemblages (thanatocoenoses) have been poorly studied in their structure and composition. Here we report data on composition and structure of a recent macro-mollusc thanatocoenosis (Gastropoda and Bivalvia, size > 2 mm) sampled on a Mediterranean sandy beach. We sampled 79 species (653 specimens), 55 of them belonging to Gastropoda (n = 466, with 8 dominant species) and 24 to Bivalvia (n = 147, with 6 dominant species). Margalef richness index showed higher values in Gastropoda compared to Bivalvia, corroborating a general pattern known for the assemblages of the Mediterranean Sea. Whittaker plot and Preston diagram displayed the differences in diversity between these two orders. Probably the high heterogeneity of local substrates provides a large suitability of habitats and niches for these mollusc assemblages, so explaining these different patterns. Although analyses of thanatocoenoses have some limitations, these data might be used for biodiversity assessments, useful for future monitoring using comparable methods and research effort.