OBJECTIVES: Validity and reliability  are important characteristics of any instrument. Generic instrument are designed for use in any population; however, their validity and reliability in particular diseases should be verified to ensure their appropriateness. In this study the authors assessed the validity and reliability of the Medical Outcomes Study Short Form–36 (SF-36), a generic instrument, in a population of patients with intradural primary spinal cord tumors (IST). METHODS: The SF-36 was administered to a cohort of patients with IST on an outpatient basis. Symptom-related data derived from a structured interview and physical examination findings were used to classify cases according to the scales of McCormick and Aminoff-Logue. Construct validity was assessed by determining whether SF-36 scores correlates with the spinal cord tumors scores (McCormick score and Aminoff-Logue score) by using the Cuzick nonparametric test for trend. The reliability of the SF-36 scores was assessed using Cronbach alpha.  RESULTS: One hundred patients with IST completed the SF-36. Construct validity was demonstrated by confirming the hypothesized relationship between SF-36 scales and the scales of McCormick (p _ 0.003), Aminoff-Logue deambulation subscale (p _ 0.025), Aminoff-Logue micturition subscale (p _ 0.013), and the Aminoff-Logue defaecation subscale (p _ 0.004). Reliability was demonstrated for all eight SF-36 domain scales and the physical component and mental component summary scales, in which Cronbach alpha satisfied the Nunnally criterion of >0.85. CONCLUSIONS: The SF-36 provides valid and reliable data on patients with IST.