Largely used in Comoros as folkloric medicine, the Tambourissa genoa is represented by six species in Comoros. T. comorensis is one of them. The present study has the objective to evaluate the phytochemical screening, total phenols and flavonoids content, antioxidant and antibacterial activities of T. comorensis extracts (ethyl acetate and methanol). Phytochemical screening concerns the presence of flavonoids in the ethyl acetate and methanol extracts and tannins only on the methanol extract. Total phenolic and flavonoids contents results are showed in a large dominance in methanol extract. The antioxidant activities were examined by 3 different methods namely 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity, reducing power scavenging activity and total antioxidant capacity. All tests showed significant dose dependent antioxidant activities. The ethyl acetate extract shows the high activity in DPPH radical scavenging activity but in reducing power assay, it’s the methanol extract which manifested the high activity. Our results on the antimicrobial activity showed the inefficiency of the extracts against most of the tested strains.