The aim of this work was to study the rat's hippocampal formation by applying the light microscopic methods. The histological methods used to explore this region of the rat's brain were the Nissl technique, the Bielschowsky block impregnation method and the rapid Golgi technique. In the Nissl preparations, we identified only three fields of the hippocampus proprius (CA1, CA3 and CA4). CA2 was distinguished in the Bielschowsky impregnated blocks. The rapid Golgi technique, according the available literature, gives the best results by using the fresh samples. In this study, we reached good results by using formalin fixed sections. The layers of the hippocampal formation were differentiated. The pyramidal and granular cells were identified together with their axons and dendrites (Fig. 9, Ref. 22). Full Text (Free, PDF) www.bmj.sk.