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In the Philippines, the relationship between macroinvertebrates and water quality remains understudied, and macroinvertebrate-based bioassessment is rarely applied. This research evaluated the water quality and the diversity of macroinvertebrates in the Sagpon and Rangas Rivers located in Camarines Sur, utilizing the Global Learning and observation to benefit the earth (GLOBE) protocols. The sampling of macroinvertebrates identified tree taxa in the Rangas River (riffle beetle, dragonfly, spider) and five in the Sagpon River (mayfly, mussel, dragonfly, litter beetle, mayfly nymph), with a greater total count observed in Sagpon (17 individuals). The Shannon-Weiner Biodiversity Index values indicated an overall low level of biodiversity, although Sagpon River received a higher score than Rangas. Physicochemical parameters revealed notable variations. Acidic conditions (pH 4.7–4.9), lower temperatures (25.9–26.7°C), higher TDS (235.78 ppm), salinity (236.44 ppm), turbidity (43.22 cm), and electroconductivity (473.33 µS/cm) were all present in Rangas River. Sagpon River, on the other hand, had lower TDS (93.44 ppm), salinity (93.33 ppm), turbidity (113.33 cm), and electroconductivity (184.89 µS/cm) and was neutral (pH 7.4–7.5) and warmer (29.4–30.7°C). While nitrate levels were higher than natural values at 5 mg/L, dissolved oxygen levels in both rivers were comparable at 7.57 mg/L. In general, the water quality of the Sagpon River was better for supporting macroinvertebrates, whereas the acidic, high-salinity, and high-conductivity conditions of the Rangas River restricted biodiversity. The results highlight how crucial it is to incorporate macroinvertebrate-based bioassessment into river monitoring in the Philippines because aquatic biodiversity is directly impacted by water quality. KEYWORDS: Biodiversity, Freshwater Macroinvertebrates, Water Quality