The proposed book gives an outline of the design, synthesis, characterization and various biological activities (antibacterial, antifungal, antituberculosis and anticancer) of novel urea/thiaourea functionalized quinazoline scaffolds. We have developed an efficient technique to introduced Suzuki C-C reaction on quinazoline and urea/thiourea moieties. The antimicrobial activity of synthesized analogs has been carried out against two Gram-positive bacteria, three Gram-negative bacteria and two fungi using paper disc diffusion method and agar streak dilution method. The synthesized analogs were further tested for their antimycobacterial activity against Mycobacterium tuberculosis H37RV using BACTEC MGIT and L. J. MIC methods. In addition, the synthesized analogs were also tested for their efficacy against prostate cancer PC3 cells using sulforhodamine B (SRB) assay to observe the variation in biological activity. The bioassay results revealed that majority of the compounds demonstrated excellent to moderate biological activity profiles. The newly synthesized compounds were characterized by IR, 1H NMR, 13C NMR and mass spectrometric analysis.