Sir: Smoking hazards are repeatedly published in newspapers but the benefits of quitting smoking are not told so often. What happens when a person quits smoking, 20 minutes after last cigarette, heart rate goes back towards normal level and blood pressure is also normalised. After 12 hours of quitting smoking, the carbon dioxide in the body decreases to lower level and blood oxygen level increases to normal. Mucus and smoking debris will begin to clear from lungs and will make breathing easier. Two to three weeks after quitting smoking, blood circulation and lung function will improve as lungs feel easier to breath. After five years of quitting smoking, the risk of long term diseases begins to fall, possibly of heart attack is almost half as compared to someone who is still smoking. QAZI JAMSHED ALAM SIDDIQUI Lahore