Erucylphosphocholine, an alkylphosphocholine anticancer drug, was employed for Langmuir monolayer characterization and liquid crystalline studies. Differential scanning calorimetry measurements together with texture observation with polarizing microscope revealed the presence of nematic phase. Film forming properties of erucylphosphocholine at the air/water interface were thoroughly investigated by means of surface pressure–area ( º –A) and electric surface potential–area ( ¢ V – A ) isotherms. The influence of such factors as subphase temper- ature, ionic strength, speed of compression, number of molecules spread at the surface on the characteristics of the º – A isotherms was investigated. Erucylphosphocholine was found to form very stable Langmuir monolayers, which are almost not influenced by experimental conditions. The liquid character of its monolayers was confirmed with both compressibility modulus values and homogeneous Brewster angle microscopy images.