The phytochemical, nutritive, cytotoxic and antibacterial analysis of Tabtaba (Nostoc linckia) species found in Lingas Baay Abra which is commonly eaten as an exotic dish was investigated using different laboratory assays. Phytochemical and nutritive analysis show the presence of carbohydrates, reducing sugars, phytosterol, phenolics, flavonoids, crude fats and proteins. Cytotoxic and genotoxic analysis of crude extract concentrations of 2.5 mg/ml, 5 mg/mL and 10 mg/ml that were tested on root meristems of A. cepa. showed that root length and mitotic index decreased as the concentrations of Tabtaba extract increased. A concentration-dependent increase in chromosome aberrations was also observed. Ethanol extract concentrations of 75%, 50% and 25% that were tested against S.aureus and E.coli showed that Tabtaba ethanolic extracts have strong antibacterial activity towards S.aureus but weak against E.coli. This study proved that the Tabtaba (Nostoc linckia) species found in Lingas Baay Abra showed potential nutritive value but contains a significant cytotoxic and genotoxic component that is considered detrimental. Further assay also revealed that it has an anti-bacterial activity towards S. aureus and E.coli at different concentrations. Basing on the results, wider exploration and analysis of Tabtaba (Nostoc linckia) species coming from other river sources in Abra, Philippines should be tested and documented. Keywords-Phycochemical, Cytotoxicity, Genotoxicity, Allium cepa, mitotic index, chromosome aberrations, zone of inhibition, S. aureus, E.coli, Philippines