The answer isn’t easy as it is not the time taken by nicotine to leave the body but it’s the time taken by the mental image that you are a chain smoker to go.  Nicotine stays in the body for about twenty to thirty minutes. One can say that within two to three days traces of nicotine would go away.  So nicotine doesn’t stay for a long time in the body. What makes nicotine an addiction or rather cigarettes or tobacco an addiction is the attachment to it. It is the habit formed over years of smoking. A pattern or programming of mind that one should smoke once you leave office or in the break time, causes a person to smoke and difficult to get rid. Physically nicotine is easily removed from the body but the pleasure one gets from smoking is difficult to quit which makes it so tough. This happens in case of a mild smoker (one who smokes 10 or fewer cigarettes), but if a person who smokes a full pack or more in a day; nicotine may remain in his body in small traces for around 30 days. This is more so if you stop smoking suddenly. Nicotine remains in the bloodstream for more time depending upon the frequency or intensity of smoking.