Tumors of the foramen magnum are rare and the incidence is between 1.6% and 2.4% of all spinal tumors; therefore the personal experiences of one neurosurgeon with this type of tumor are necessarily limited. This unfamiliarity, combined with the curious presentation of some of the lesions due to the complex anatomy of this region, has made the diagnosis of foramen magnum tumors difficult. Unless this is kept in mind, one might fail to consider these lesions in the differential diagnosis, causing a delay in appropriate treatment until permanent damage results. The purpose of this paper is to describe the symptomatology and diagnosis, as well as the surgical treatment, of 21 cases of foramen magnum tumor encountered at our clinic during the last 10 years.