Stilbene, chalcone and flavanones are three major classes of molecules, which can be found in plants as secondary metabolites. Derivatives of those may possess variety of biological activities. In this study it is aimed to synthesize a hybrid molecule which may show the biological activities of both flavanone and stilbene, or chalcone and stilbene simultaneously. For this purpose previously synthesized 11 simple chalcone, flavanone and stilbene derivatives and 31 stilbene-fused chalcones and stilbene-fused flavanones were tested for their cytotoxic activities in prostate cancer cell line (PC-3) and breast cancer cell line (MCF-7) by using MTT assay. Then aromatase inhibition properties of simple chalcones, flavanones, stilbenes, stilbene-fused chalcones and stilbene-fused flavanones were studied. Results of the study were evaluated in potential of the hybrid system to carry out more than one biological activity and mimicking performance of the simple ones. Results indicate that tested simple chalcone and flavanone derivatives are more cytotoxic than simple stilbenes in both cancer cell lines. On the contrary, simple stilbene structures were much more successful in aromatase inhibition assays. Cytotoxic activity profiles of stilbene-fused chalcones in cancer cells show that those molecules mostly mimic the simple chalcone structures. On the other hand, flavanones lost their cytotoxic activities when they were fused with stilbenes. In addition, aromatase inhibition assay showed that stilbene-fused chalcones again do mimic the simple chalcones but not simple stilbenes. In the same assays, stilbene-fused flavanones may mimic both simple flavanones and simple stilbenes by depending on the type and position of the substituent in terminal aromatic rings.