Background: Spinal manipulative therapy is used millions of times every year to relieve symptoms from biomechanic dysfunction of the cervical spine. Concern about cerebrovascular accidents after cervical manipulative therapy is common but rarely reported. Premanipulative tests of the vertebral artery are presumed to identify patients at risk but controversy exists about their usefulness.Objective: The aim of this study was to examine vertebral artery blood flow in patients with a positive premanipulative test for contraindication to spinal manipulative therapy and to investigate if chiropractors would reconsider treating such patients if dynamic vascular Doppler examination was normal.Design and setting: A prospective study at a university hospital vascular laboratory.Methods: Chiropractors in private practice from 3 Danish counties referred patients with a positive premanipulative test for an examination of vertebral artery blood flow. Premanipulative testing was performed by an experienced chiropractor. Flow velocities were measured in both vertebral arteries by color duplex sonography. In addition, chiropractors were asked if they would treat their patient despite a positive premanipulative test if the vascular ultrasound examination was normal.Results: A total of 20 consecutive patients with a positive premanipulative test were referred. Five were excluded because symptoms could not be reproduced during the vascular examination. In the remaining patients, no significant difference in peak flow velocity or time-averaged mean flow velocity with different head positions was found. Nineteen of 21 chiropractors would treat a patient with a positive premanipulative test if the vascular examination was normal. Eight of the patients with a positive manipulative test were treated without complications. Six are now symptom-free, and 2 have improved symptoms. The remaining 8 patients refused manipulation and continue to have the same symptoms.Conclusion: It appears that a positive premanipulative test is not an absolute contraindication to manipulation of the cervical spine. If the test is able to identify patients at risk for cerebrovascular accidents, we suggest patients with a reproducible positive test should be referred for a duplex examination of the vertebral artery flow. If duplex flow is normal, the patient should be eligible for cervical manipulation despite the positive premanipulative test.