How can I get someone to quit smoking?

As a nonsmoker who feels the same way about the smokers she loves, I feel your pain. I think one of the hardest parts is to sit back and do nothing, even though there's nothing you can really do to make things better (as evidenced by all the advice above). I took the approach of saying to one smoking friend, "I'm not going to bug you about smoking, because I know that wouldn't help. But if you ever get an inkling that you would like to quit, please PLEASE lean on me for whatever support you need. I will call quit-smoking programs for info, I will take you out for ice cream or movies to distract you, and I will be your biggest cheerleader. And that's all I'm going to say about it, so don't forget." And I haven't brought it up since. My friend still smokes, but I like to think that someday he might take me up on the offer. At the very least, it made me feel like I had done as much as I could to help, tiny as it was, so I could stop feeling guilty about my nonaction.

You can't force someone to quit -- they have to want to. And no, this doesn't mean that you should badger them with info and statistics, either, in a sort of awareness campaign effort to make them want to stop smoking. Most people know about the dangers of smoking. Aside from telling the person that you love them and fear for their health, I don't think there's much you can do to cajole them.

I disagree with most of the answers. A person decides to quit smoking because they perceive the cost to be too high. Sometimes someone else can force the issue by raising the cost. On our third date, my husband told me he would not see me again if I continued to smoke. I liked him better than I liked cigarettes, so it was done. I'll never start again because the drama quotient would be way too high. Taxes have been very successful at reducing smoking rates because many people can't afford to smoke. The tipping point will be different for each person, and it depends how much leverage you have. If you give them an ultimatum (I will never speak to you again unless you quit), you must be prepared for them to pick cigarettes over you.

As a smoker who has chafed at people making couched remarks, nothing you say will work no matter how subtle and incisive you think your newest tactic is. Smoking and wanting someone to quit are separated by a gulf as big as the connection between eating food and growing it. How effective at converting people to gardening do you think it would be to bring up growing food every time they eat? "Wow, you like food. You should grow some." "Have you started growing food yet?" "How can you just eat bought food like that, don't you know it would be much better tasting if you grew it yourself?" "Why are you still not gardening?" The only thing I would say you can do is to start taking them hiking and exercising all the time.

Former smoker here, and yes, ultimately one has to want to quit for oneself. The thing that really helped me was Allen Carr's book http://www.amazon.com/exec/obidos/ASIN/1402718616/metafilter-20/ref=nosim/. Horribly written, cheesy as hell, but in some strange way it worked. I can't explain why, really, and I had to read it twice, but really, it worked. Why not buy them a copy and ask them to read it? Won't cost them more than a couple hours of their time. And no, I don't work for, nor am I, Allen Carr.

Unless he's exceptionally sheltered or has a disability that might make it difficult for him to understand the information, he's aware of the dangers of smoking. Tell him one final time: "Hey, I'm going to stop being an asshole about this, but I still really want you to quit. I don't mean to treat you like you're too stupid to know better or that I'm too stupid to know how incredibly hard it is to quit. When you're ready to do it, I'm totally behind you and will do anything you need to help." And then leave it alone until you're asked for help.

Nurses in oncology wards- nurses who watch people die in agonizing pain from cancer every day- are often smokers. http://www.ejoncologynursing.com/article/S1462-3889%2808%2900064-1/abstract. This is not a decision that can be made for someone else, and no amount of evidence, data, or nagging will work.

Hate to break it to you, but you can't. He will quit when he wants to. It's all on him. Despite a ton of nagging, scare tactics (look! This is what it's doing to your body), pleading, death of a friend due to lung cancer, and a pet that died of lung difficulties due to their secondhand smoke.. my family member continues to smoke.

If you have never been a regular smoker then it's easy to underestimate or dismiss just how addictive it can be. Many millions of dollars worth of research over many decades has gone into perfecting what is already a naturally addictive substance, making it as potent and nasty as possible. It burrows deep into the brain (figuratively) and doesn't let go. If you have never experienced this first hand then it might seem odd that someone would want to continue this gross habit that doesn't really seem to have many benefits. But trust me, they don't do it because they necessarily want to, they do it because their brain won't let them stop.