Congenital neutropenia or Kostmann syndrome is an inherited disorder manifesting in infancy and characterized by severe bacterial infections. The myelodysplastic syndromes(MDS) are a group of stem cell disorders characterized by a reduction in one or more elements of the peripheral blood. This paper reports a case of Kostmann syndrome and MDS with oral complications such as generalized gingivitis and periodontitis, oral mucosal ulcer, petechiae. The features of these syndromes are reviewed and their oral manifestations and significance to dental management outlined.