Introduction and objective. Neurons besides its ability to selectively detect signals from their surrounding, are able to integrate then in time and space when transmitting their message to other cells. This exceptional ability of the neuron is mainly due to the composition and characteristics of its plasma membrane. In this review, starting with a description of the general principles of cell membrane organization, on which the nerve cell membrane structure is based, we describe the structures and functions which are unique and peculiar to the neuronal membrane and its implications in pathological processes. Development. This review article starts with a description of the lipids forming the neuronal membrane, and the forces which maintain their cohesion to form the basic structure of the membrane. We describe some of the intrinsic biophysical properties biological bilayers, and also make special mention of the neuronal membrane proteins, both peripheral and integral proteins which are, finally, responsible for specificity and functional differentiation of the neurons. Conclusions. Now a days it is becoming clearer that the knowledge of the neuronal membrane at the molecular level, specially the proteins involved in neuronal activity, is basic to understand neuronal physiology and pathology. Many disorders of the nervous system have their origins in defective synthesis or incorrect functioning of a particular protein in the neuronal membrane [REV NEUROL 1998; 26: 232-9].