Background: Ankylosing spondylitis (AS) is an inflammatory condition with prolonged pain that results in loss of function. Diagnosis delay in the past had little effect on the prognosis of AS because of the lack of an appropriate treatment options. It is now possible to reduce the advancement of AS in patients who have had it for a shorter time since biological treatment is highly effective, early diagnosis in AS has become increasingly critical. Objective: The aim of the work was to determine the relation between delay of treatment for ankylosing spondylitis patients and structural changes by Bath ankylosing spondylitis radiology index (BASRI) as well as Modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS). Patients and Methods: At Zagazig University Hospitals, the Department of Rheumatology and Rehabilitation, the Faculty of Medicine, 42 patients with Ankylosing spondylitis were studied using the modified criteria of New York for Ankylosing spondylitis. Data were recorded from taking complete history, local as well as general examination and laboratory investigations involved; complete blood picture, kidney function tests, CRP, ESR and complete urine analysis. The radiological progression was assessed by mSASSS, and BASRI.  Results: The present results showed that mean patients age at disease onset and at diagnosis were 23.9, and 35.14 respectively, the mean of diagnosis delay was 7.66 years. There is a significant positive association between period of delay of patients to intake proper treatment and BASRI, and mSASSS (p < 0.05). Conclusion: It could be concluded that diagnosis delay of AS is associated with more structural damage detected by mSASSS and BASRI that reflects the importance of early diagnosis.