In this study, optical transmittance of mixed nematic liquid crystals (MNLCs) was investigated in terms of temperature variations and rotational angle of polarizer through electrooptic methods under dc electric field. The optical transmittances of the mixed structures, which were prepared at certain proportions, were measured in their phase transition region as contained molecular anisotropy. In the results of measurements, while the optical transmittance is in low level in the nematic phase, the optical transmittance was observed in the highest level by the nematic-isotropic phase transition. It was also observed that the domain structure of the material was affected considerably by the applied electric field as the temperature changes and phase transition region of the mixed structures had broader range than by the pure crystalline structure and its phase transition temperature was changed by the molecular anisotropy. (c) 2008 Elsevier B.V. All rights reserved.