Intramedullary spinal cord abscesses are an uncommon entity with 73 cases reported in the literature; the first case was reported in 1830. Sixty-seven percent of abscesses occur in the first 4 decades of life. Staphylococcus and Streptococcus are the most common organisms; 25% of patients have negative intraoperative cultures. The primary source of the infection could be found, in only 45% of patients. Most of these infections are secondary to metastatic spread from infections of the lung, endocarditis, genitourinary tract; 10 reports have described an intramedullary abscess secondary to a dermal sinus. The signs and symptoms depend on the location of the lesion; the thoracic spine is the most commonly area involved. Patients are usually divided into three clinical groups; acute onset (symptoms less than 1 wk), subacute onset (symptoms up to 6 wk), and chronic course (symptoms more than 6 wk). Patients with the acute form are more likely to have a fever and an elevated white blood cell count and may show either a partial or complete transverse myelitis picture. The patients with chronic abscesses are less likely to have fever and leukocytosis, and their symptoms often mimic those of an intramedullary spinal tumour. The erythrocyte sedimentation rate tends to be elevated in all patients regardless of their clinical findings. CSF cultures are usually sterile. Plain x-rays of the spine are often normal. A myelogram in conjunction with a computed tomographic scan may show the intramedullary lesion. MRI studies usually demonstrate intramedullary lesions with exceptional clarity; the use of gadolinium with T1-weighted MRI studies enhances the abscess wall.(ABSTRACT TRUNCATED AT 250 WORDS)