Dendritic cells are a heterogenous group of antigen presenting cells showing characteristic morphology, expression of certain cell surface molecules and the capability to efficiently activate the immune system. This study aimed at determination of the morphology and distribution of dendritic cells, histologically and immunohistochemically using S100 protein in normal and hyperplastic nodes. Fifty cases were included in this study; ten of normal lymph nodes and forty cases diagnosed as nodal hyperplasia. Histological assessment of specimens was done using H&E to classify hyperplastic lymph nodes as follows: a-17 specimens of follicular pattern. b-b- 10 specimens of sinus pattern.c- 8 specimens of diffuse paracortical hyperplasia.d- 5 specimens of mixed pattern.The dendritic cells were detected histologically by H&E stain as irregular cells with eccentric nuclei, but better visualized by S100A protein monoclonal antibody using the standard ABC method. Quantitative morphometric studies including the mean area % and the mean average diameter of S100 immunopositive interdigitating dendritic cells were done using an image analyzer. All data were statistically analyzed. Dendritic cells were larger in hyperplastic nodes than in normal lymph nodes. Follicular dendritic cells were detected in the germinal centres of cortical follicles of normal and hyperplastic nodes (follicular variant and mixed pattern). Interdigitating dendritic cells were located in the paracortex of normal and hyperplastic nodes (diffuse paracortical hyperplasia & mixed pattern). Regarding immunoreactivity using S100A protein monoclonal antibody; follicular dendritic cells were negative in all examined specimens, while interdigitating dendritic cells were positively stained, with higher density in the diffuse pattern followed by mixed pattern than normal lymph nodes. From the current results we could conclude that:1-S100A protein monoclonal antibody is a useful marker for interdigitating dendritic cells in the lymph nodes but not for follicular dendritic cells.2-Determination of the pattern of lymphoid hyperplasia is a must, as it may point to the aetiology of lymphadenopathy.3-Further survey studies on dendritic cells are required for better understanding the origin and assessment of the role of dendritic cells in activation of immune system.