A 62-year-old male kidney transplant recipient presented with a penile ulcer, initially misdiagnosed as herpes simplex. Biopsy revealed granulomatous inflammation, and subsequent PCR confirmed Mycobacterium tuberculosis complex. Further investigation uncovered miliary tuberculosis affecting the lungs, liver, and spleen. The patient, on immunosuppressants, was successfully treated with anti-tuberculous therapy. This case highlights how tuberculosis can present atypically in immunocompromised individuals, with a rare extrapulmonary manifestation like penile involvement being the sentinel sign of disseminated disease. Prompt recognition of unusual presentations is crucial for early diagnosis and management in this vulnerable population. Teaching point: Atypical extrapulmonary tuberculosis can be the first manifestation of disseminated disease in immunocompromised patients, requiring high clinical suspicion.