ABSTRACT We found that a new stable state of porphyrin monolayer can be induced by liquid crystal molecules. We measured the surface pressure per area of the monolayer at various molar fractions of liquid crystal. The polarity and orientation of liquid crystal molecules were investigated by recording the surface potential value of the monolayer. We found that the dispersion of porphyrin in a liquid crystal solution led to changes in the surface structure and the surface pressure of the monolayer at the air–water interface. Therefore, the surface potential records can be used to control the orientation of liquid crystal and the formation of mono- or multilayers of Langmuir thin film. The plots obtained for solutions with a mole fraction of liquid crystal greater than 0.333 showed repulsive interactions between porphyrin and liquid crystal molecules.