The depositional history of Callao Cave in Peñablanca, Cagayan Province, northern Luzon is known for its long occupations and presence of a fossil hominid dated to ~67ka. While the reconstruction of the Palaeolithic subsistence economy in northern Luzon has recognized various models from a combination of lithic, sediment, floral, and faunal analysis, less is known of the Neolithic occupation of Callao Cave. A preliminary analysis of the molluscan remains recovered from the 2020 re-excavation of Callao Cave was carried out to address how an archaeomalacological analysis could illuminate human subsistence behavior and provide a better understanding of the Lapita culture corresponding to the arrival of Neolithic Austronesian-speaking peoples in northern Luzon. Preliminary molluscan taxonomic characterization showed an abundance of terrestrial and freshwater gastropods associated with the Neolithic layer. Although the shell remains were too scarce to affirm subsistence behavior, the presence of edible species still opens the possibility considering the appearance of potentially burnt plant and animal remains. The abundance of Cyclophorus spp. and Helicostyla spp. land snails suggests a moist tropical climate and forested limestone terrain, while the abundance of freshwater thiarids supports the previously postulated Neolithic wetland conditions in Cagayan Valley. Lastly, the recovered Conus spp. discs and beads share morphological similarities with those found in burial contexts at Leta Leta (Palawan) and Maitum (Sarangani). This preliminary analysis of the Callao Cave shell specimens warrants a large-scale study to contribute to the understanding of the Neolithic subsistence economy, local environment, cultural practices, and trade networks, possibly associated with Austronesian-speaking peoples.