It is known that 1,2,3-thiadiazoles and their derivatives – benzo[b]thiophenes – have a high synthetic potential as well as a wide spectrum of biological activity. In particular, 1,2,3-thiadiazole derivatives exhibit antivirus, antitumor, herbicide, fungicide, and insecticide activity. Among the beneficial properties found for benzo[b]thiophene derivatives are anticancer, antidiabetic, antituberculosis, antimalarial, antifungal, antidepressant, anticonvulsant, antihyperglycemic, antiangiogenic, antimitotic, antiinflammatory and analgesic properties. The above information on 1,2,3-thiadiazole and benzo[b]thiophene derivatives encouraged us to design and synthesize new bioactive agents with the 4-(2-hydroxyaryl)-1,2,3-thidiazole, 4-(1,2,3-thiadiazol-4-yl)furan and 2-aminobenzo[b]thiophene structures. The synthesized products were tested in vitro against human erythroleukemia (K562), cervical carcinoma (HeLa), breast cancer (MCF7), T lymphocyte (Jurkat) cell lines. According to the results of the research, some derivatives showed potent antiproliferative activity against used cell lines. Obtained experimental data can stimulate further search for pharmacologically active compounds among 4-(2-hydroxyaryl)-1,2,3-thidiazole, 4-(1,2,3-thiadiazol-4-yl)furan and 2-aminobenzo[b]thiophene derivatives.