Nucleolar organizer region (NORs) are DNA segments in ribasomal RNA (rRNA) synthesis. Some special proteins which have relation with NORs are know as "NOR associated protein "or Ag-NOR". Ag-NOR technique is a special silver-staining technique which makes the Ag-NOR examination possible by light microscopy. Avarage Ag-NOR number, Cell poliferation index are gathering more interest recently. Ag-NOR technique seems to be of value in the differentiation of normal and neoplastic cells. The paraffin bloc sections of 40 hypophese adenoma and 25 normal adult adenohypophese are stained with Ag-NOR technique, in addition touching sections of 10 hypophese adenomas are evaluated with 15 minute staining period of Ag-NOR technique. The difference in the average Ag-NOR number in the paraffin sections of hypophese adenomas and normal adult adeno hypophese is highly significant (P<0.001).There was nodifference in the paraffin sections and the touching sections. We think, the modified Ag-NOR technique we use in cytologic material, can be effectively used during the adenomectomy operations in the differentiation of normal hypophese tissue and adenoma tissue.