Background: The study aims to analyse expression of stem cell marker aldehyde dehydrogenases 1 (ALDH1) by Immunohistochemistry (IHC) in non-neoplastic and neoplastic lesions of the gall bladder. Materials and Methods: The study was accomplished at the Department of Pathology Era’s Lucknow Medical College and Hospital, Lucknow. A total of 105 cases were enrolled for the study. The paraffin embedded tissue was subjected to haematoxylin and eosin staining. Immunohistochemistry was done further for the expression of ALDH1 stem cell marker, IHC was further done