A series of novel quinazolinone derivatives (II-(3a-3j) [(E)-7-chloro-2-(4-((4-substituted benzylidene) amino) phenyl) quinazolin- 4(3H)-one] were synthesised, characterized and biological screened for their in vitro antibacterial, anthelmintic and anticancer activity. All compounds, were synthesized through two steps process and structurally conformed by FTIR, 1HNMR and Mass spectroscopy. Their anticancer activity was assessed using MTT method against MCF-7 and SKOV3 cell lines, the anthelmintic activity was carried out by using Indian Earth warms and the antibacterial activity was carried out by Cup-plate diffusion method. In addition, molecular docking studies was assessed using Autodock Vina. The compound II-3c (IC50 value of 23.24µg against MCF-7 and 21.05µg against SKVO3) exhibited good anticancer activity compared with Doxorubicin as standard. In anthelmintic and antibacterial screening, the compounds, II-3c, II-3h and II-3j have shown excellent anthelmintic activity and compounds II-3b, II-3d, II-3f, II-3h and II-3j showed significant antibacterial activity.