ABSTRACT
This study was carried out on 80 dry human sacra in meenakshi medical college Anatomical variations inmorphology and morphometry of sacral hiatus. Various shapes of sacral hiatus were observed which includedinverted U (66.3%), inverted V (11.3%), irregular (11.3%), dumbbell (3.8%) Agenesis Of the dorsal (6.3%) and bifid(1.3%). The apex of sacral hiatus was commonly found at the level of 4th sacral vertebra in 76.0%. the meanlength of sacral hiatus was 22.9 mm. The mean anteroposterior diameter of sacral canal at the apex of sacralhiatus was 4.97 mm. Narrowing of sacral canal at the apex of sacral hiatus, diameter less than 4mm, wasobserved to be significantly high, (36%). The knowledge of anatomical variations of sacral hiatus is significantwhile administration of caudal epidural anaesthesia and it may help to improve its success rate