Tuberculosis was a major public health problem in the nineteenth-century Ottoman Empire. This study presents an iconodiagnostic analysis of Kökenoğlu Rıza Efendi (1871) by Osman Hamdi Bey, a portrait completed approximately ten days before the sitter's documented death from tuberculosis. The painting was evaluated according to published iconodiagnostic guidelines and interpreted alongside historical documentation and clinical descriptions of end-stage pulmonary tuberculosis. Visual analysis revealed marked facial cachexia, including hollowed cheeks, prominent zygomatic bones, deepened nasolabial folds, sunken orbital regions with periorbital shadowing, pallor, and an elongated cervicomandibular contour. The artist's use of chiaroscuro further accentuates these features. Although individual findings may reflect ageing or artistic convention, their combination, together with the documented historical evidence, is compatible with the characteristic physical appearance of end-stage pulmonary tuberculosis. This portrait represents may therefore represent a rare historical visual record of end-stage tuberculosis and highlights the value of iconodiagnosis in medical humanities and the historical interpretation of disease.