Nicotine is hazardous to human body and adversely affects almost all systems of the body. Side stream smoke also called second hand smoke is as hazardous as for primary smokers. An increased risk of development of chronic obstructive lung disease and lung cancers has been reported in many studies. Smoke free work places seem to be the only option to reduce such hazards. This strategy must go on simultaneously along with established smoking cessation programs. An insight into the factors leading to nicotine addiction must also be taken care of. Nicotine dependence is a craving which leads to the compulsive use of nicotine containing products, physiologic tolerance (needs to use increase amounts of nicotine to achieve desired effects), nicotine withdrawal upon discontinuation (symptoms being craving, irritability, anger, anxiety, depression, increased appetite) and continued use despite a lot of problems Nicotine the substance responsible for addiction is disastrous, causing harm to almost every organ of the body. Nicotine use causes an increase in the dopamine, glutamate, gamma-aminobutyric acid release and these give feeling of pleasure and calmness. Withdrawal symptoms occur due to decrease of dopamine in period of abstinence and corticotropin releasing factor may play a key role in withdrawal.