Congenital neutropenia is characterized by a severe reduction in absolute neutrophil counts, resulting in an almost total absence of neutrophils. It is well known that severe neutropenia affects periodontal status. Oral manifestations include ulcerations, gingival desquamation, gingival inflammation, attachment loss, and alveolar bone loss which may result in tooth loss. Treatment with granulocyte-colony stimulating factor (G-CSF) may improve this periodontal condition. This article reports the relationship between periodontal disease status and peripheral neutrophil levels in two consanguineous siblings with severe congenital neutropenia who did not receive routine G-CSF for 2 years prior to examination. Both siblings were given scaling, root planing, and periodontal prophylaxis in regular follow-up visits. This report demonstrates that periodontal therapy supported by adequate oral hygiene may result in restoration of neutrophil counts in siblings with congenital neutropenia.