A study was undertaken on 60 gingival specimens from 33 patients in order to see if a correlation exists between the Gingival Index and a newly developed histologic classification. Each specimen was scored clinically using the Gingival Index immediately prior to surgical excision. The quantitative morphologic classification with a range from 1 to 3 was based upon the number of functioning involved and uninvolved blood vessels/mm2, the number of mononuclear cells/mm2, the spread of inflammation and the number of polymorphonuclear cells/mm2. From these results of this study the following conclusions can be made: the findings of this study support the choice of these morphologic criteria because they were shown to reflect closely the criteria used for the Gingival Index. However, the most clearly identifiable criteria of the GI, the bleeding tendency, does not correlate closely with its morphologic criteria, (the number of vessels). With a more severe morphologic inflammatory involvement the plasma cells were predominantly mononuclear. Whereas the GI reflect the overall condition of gingival tissues, the morphologic classification proposed reflects more closely the state of involvement of oral and/or sulcular tissues.