Inflammatory periodontaldisease arises as a response to bacterial plaque. This response, however, may be modified by systemic factors such as nutritional deficiency, hormonal imbalance or severe systemic disease. One such systemic disease that may modify host response to local etiologic factors is systemic lupus erythematosus (SLE). Depression of thrombocyte production is very rarely associated with SLE. A search of the medical literature has revealed only one such reported case. The case history that follows is of a 17‐year‐old black female with severe gingivitis and spontaneous gingival bleeding associated with systemic lupus erythematosus and amegakaryocytic thrombocytopenia. It is believed to be the first such case reported in the dental literature. The clinical, radiographic and hematologic findings will be presented and the medical and periodontal therapy discussed.