Sulfur mustard (SM) is an alkylating chemical warfare agent with high military significance due to its high toxicity, resistance and availability. SM was widely used in military conflicts, the last being the Iran-Iraq war with more than 100,000 Iranians exposed, one-third of whom are still suffering from late effects. The intensity of the delayed complications correlates to the extent, the area and the route of exposure. The clinical manifestations most commonly involve respiratory, ocular and dermal effects. Respiratory complications include dyspnea, cough and expectorations and various obstructive and restrictive lung diseases. Dermal complications are itching, burning sensation, blisters, dry skin, dermatitis and pigmentary changes. Ocular complications include photophobia, red eye, tearing, corneal ulcers and blindness. Although the picture remains incomplete the major mechanisms responsible for the clinical and pathological effects of SM are: DNA alkylation and cross-linking, protein modification and membrane damage in addition to induction of inflammatory mediators in the target tissues causing extensive necrosis, apoptosis and loss of tissue structure. The current report reviews long-term complications of SM exposure, focusing on new treatments tested in clinical trials conducted on humans. Such treatments include: N-acetyl cysteine, bronchodilators, corticosteroids, Interferon-gamma, furosemide and morphine for the respiratory complications. Ocular complications may entail: Invasive procedures treating corneal complication, limbal ischemia and stem cell deficiency. Treatment for dermatological complications include: anti-depressants, pimercrolimus, Unna's boot, capsaicin, phenol and menthol, Aloe vera and olive oil, curcumin and Interferon-gamma.