The interfacial properties and interactions between phosphatidylcholine (PC) vesicles and surfaces (air/water, oil/water, or oil/ethanol) were investigated with regard to the stability of the dispersed systems. Understanding interactions between the PC vesicles and different solutions is very important to make it easier to recognize various physiological functions of membranes. The interactions and possibility of creating stable PC-based systems were studied by different techniques, such as surface tension, microelectrophoresis, and static and dynamic light scattering measurements. Besides determining the physicochemical characteristics, another aim of this work was to develop PC-based (micro)emulsions and study the changes in their microstructures. Dispersion stability by droplet size and zeta potential determination were correlated with the changes of interfacial tension. Pseudoternary phase diagrams have been constructed to evaluate the phase behavior of the systems containing n-tetradecane/phosphatidylcholine and water (or ethanol) at different weight ratios. The presence of ethanol changes the area per lipid molecule and the layer thickness, therefore the capability of phospholipid adsorption at the oil/alcohol interface was dependent on the ethanol concentration and increases with its increase. Using aqueous-ethanolic phase enables us to obtain a small region of o/w and w/o PC-based microemulsions. This study has shown that nature of biosurfactant, ethanol concentration, and proportion of the oil to water phase are the most important factors for processing and stability of the phosphatidylcholine-based emulsions. The obtained results expand the characteristics of the oil/phospholipid systems, which may lead to large application potential.