Sacral hiatus is caudal opening of sacral canal. Caudal epidural anaesthesia for various therapeutic and diagnostic procedures is administered through sacral hiatus. 25% failure rate of caudal epidural block has been reported in literature. The failure rate of this procedure may be due to variant anatomical features of sacral hiatus. Hence knowing the anatomical variations in shape, size, level of apex and baseof sacral hiatusis of paramount importance to clinicians to reduce failure rate of caudal epidural block. For this review, literature search was done in the department of anatomy using databases, Scielo, Scopmed, medline, pubmed and Wiley online library. Only English language articles and standard text books were referred. The anatomical features of sacral hiatus has immense value to orthopaedic surgeons, obstretricians, paediatricians, anaesthecians and anatomists. This review will update and consolidate the information on sacral hiatus and will serve a ready reference for future researchers and clinicians.