A wide gamut of the swellings and tumors of the non-odontogenic origin have been included in this chapter. Some are just lesions originating from the minor irritations of the oral cavity and they have been included in the beginning of the chapter due to their relatively common occurrence. In the other groups most are self-limiting and come under the benign banner and the really wicked ones, the malignant groups are those that cause wanton destruction of tissues and need very aggressive treatment. The diverse group of lesions discussed in this chapter range from the reactive, to hamartomatous to benign to the fatally malignant. This chapter is merely indicative of how extensive research and literature is being developed on each lesion. The primary care dentist must just know how to distinguish between the reactive and the malignant. Remember when in doubt, histopathology, radiography and hematology will come to your help. Referral to Oral Physicians is the next logical choice.