Two series of Benzothiazole, Quinazolinone derivatives bearing guanidinopropanoic acid (38 compounds including 27 intermediates) and one series of Schiff base derivatives (14 compounds) were synthesized, characterized then evaluated for their cytotoxicity against human cervix cell line (HeLa) by MTT assay; antimicrobial activity against 11 pathogenic bacteria, 10 pathogenic fungus using standard of ciprofloxacin and Clotrimazole respectively. Compounds 13–18 showed significant activity against HeLa with IC50 range of 2–550 μM. Compound 3-(3-(6-hydroxybenzo[d]thiazol-2-yl)guanidino)propanoic acid (18) showed potent activity against human HeLa cell line with the half maximal inhibitory concentration (IC50) values of 1.8 μM which was close to the value of the positive control, doxorubicin. Antimicrobial result indicated that, compounds showed differential activity against the tested fungus and bacteria. Compounds 11, 14, 38 and 49 exhibited potent antibacterial and antifungal activity.