Coastal boulder deposits serve as sedimentary markers of extreme wave events (EWEs), offering valuable insights through their morphology and spatial distribution. In Pasuquin, Ilocos Norte, and other parts of northwest Luzon, Holocene emergent reefs are overlain by extensive fields of carbonate boulders. This study examined 198 boulders across two sites, Davila (north) and Dilavo (south). The emergent reef measured 0.21 below mean sea level (corrected using Currimao tide station), features spur-and-groove morphology, solution pools, and occasional fossil microatolls. Most boulder are flat blocks with varied orientations, the largest weighing up to 31.49 t, and are inferred to originate from the underlying reed platform based on morphology and satellite imagery. Spatial and bivariate statistical analyses show boulder clustering in Dilavo, with a multimodal weight distribution and a higher proportion of boulders over 9 t compared to Davila. This suggests that coastal geomorphology significantly influences boulder distribution, given both sites were likely affected by the same EWE. The estimated minimum flow velocities and minimum wave heights of the inferred EWEs needed to transport the boulders are 1.75 to 6.90 m/s and 0.34 to 7.63 m respectively. Framework corals on the boulders yielded 230Th ages ranging from 1262.6 ± 4.8 to 2815.9 ± 6.7 YBP (relative to AD 1950), potentially marking the timing of initial displacement. In contrast, fossil corals within the emergent reef dated between 444.9 ± 1.8 and 677.9 ± 2.2 YBP, possibly indicating younger uplift. These findings enhance understanding of past EWEs in northern Luzon and contribute to future coastal hazard assessment in the region.