Abstract: Objective To investigate the clinical diagnosis and aviation medical evaluation principles of syringomyelia (SM) in aircrew. Methods The diagnosis and medical assessment of SM in 4 pilots admitted to our hospital from 2002 to 2014 were retrospectively analyzed. Suggestions for the medical assessment of SM in aircrew were put forward by summarizing the clinical data and reviewing its related literatures. Results The pilots who admitted to hospital had different reasons: one for physical examination for transferring to high performance aircraft, one for head injury, two for indisposition of neck, none of them displayed with dissociated sensory disorder, muscle atrophy and no signs were found in physical examination. The diagnosis of SM was established according to the spinal cavity in MRI. They were permitted to return to fight and showed no manifestation of SM during the following 1 to 12 years fight and no progress in MRI. Conclusion Pilots with SM can be given fight qualifcation if the clinical symptoms are not typical. Flight conclusion should be made according to the overall assessment of the disease, aircrafts species, fight duty, and will of individual pilot. Pilots who are specially permitted to fy should be closely followed up.