In this study new chalcone derivative (2E)-3-(1-benzothiophen-2-yl)-1-(4-hydroxyphenyl)prop-2-en-l-one (I), which has important pharmacological applications, was designed and synthesized. IR, NMR and LC-MS/MS empirical methods were used in order to confirm the molecular structure of the synthesized compound I. Both two tautomeric forms of the molecule were optimized by using density functional theory (DFT) method. The structural parameters formed after optimization and structural parameters obtained from similar compounds by X-ray diffraction show a good correlation. The theoretical and experimental results of IR and NMR are generally compatible, but difference arises between some values. This difference shows the existence of O-H center dot center dot center dot O type intermolecular hydrogen bond. By using its UV-Vis data, the visible absorption maximums of the molecule were analyzed. Compound I was tested against kind of Leishmania major from the point of antileishmanial activity, against kind of Candida albicans from the point of antifungal activity and against fourteen kinds of bacteria from the point of antibacterial activity in this study. The test results showed, that compound I was effective on eight kinds of bacteria and the activity strength on six bacteria among the eight was MIC: 5000 mu g/mL and on the rest two kinds MIC: 1250 mu g/mL. Besides, it was also found out, that compound I has MIC: 5000 mu g/mL antileishmanial activity. Since bacterial and parasitic infections form serious health problems globally, compound I may be a medication candidate in future; if its antibacterial and antiparasitic effect are taken into consideration.