Background <p>Assessing disease activity and severity in ulcerative colitis (UC) requires a thorough evaluation that includes clinical symptoms, endoscopic findings, and histological results. This study aimed to explore the relationship among clinical, endoscopic, and histopathological parameters in Egyptian patients with UC.</p> Methods <p>Retrospective analysis of 50 UC patients was conducted using clinical, endoscopic, and histological assessments. Histological activity was evaluated by the recently developed Inflammatory Bowel Disease—Distribution, Chronicity, Activity (IBD-DCA) score while clinical and endoscopic activities were assessed by the partial Mayo score (pMayo score) and the Mayo Endoscopic Subscore (MES), respectively.</p> Results <p>Significant associations were found between the MES grade and IBD-DCA parameters D and C (<i>p</i> = 0.05); however, no significant association was observed between the MES grade and the overall IBD-DCA grade or parameter A (<i>p</i> = 0.07). Notably, all patients in endoscopic remission (MES 0 or 1) continued to exhibit histological activity. A highly significant association was identified between the pMayo score and the IBD-DCA grade (<i>p</i> = 0.01). A highly significant association was also noted between the pMayo score and the MES grade (<i>p</i> = 0.02), as well as between clinical remission and the MES (<i>p</i> &lt; 0.001).</p> Conclusion <p>The study demonstrates significant associations between clinical activity (pMayo score) and histological activity (IBD-DCA score),&#xa0;as well as between clinical and endoscopic activities in Egyptian patients with UC.</p>