Small bowel biopsy remains the gold standard for diagnosing celiac disease (CD). Intraepithelial lymphocytosis in the context of villous atrophy is considered a characteristic histologic finding of CD. However, studies have also indicated that the detection of intraepithelial lymphocytosis in the absence of villous atrophy is not specific for CD, having been documented in other small intestinal disorders. This review summarizes key aspects regarding the histopathologic assessment, impact of the site and number of small bowel biopsy samples on diagnosis, old and emerging classifications, and benefit of standardized pathology report in the diagnostic workup of CD.