A recent rigorous systematic review and meta-analysis, that combines all high quality trials (the 'highest' form of evidence based medicine) has confirmed the benefit of acupuncture in helping those trying to give up tobacco. Acupuncture was found to have a significant benefit in helping people stop smoking immediately after a course of treatment and at both 3 and 6 months following treatment. Acupuncture showed maximum benefit three months after the completion of a course of treatment, when those treated with acupuncture were two and a half times more likely to have stopped smoking than those who received other treatments. Acupuncture may work by affecting the smoker's taste of tobacco and their desire to smoke.
My own view based on clinical experience is that acupuncture can indeed be a useful support to those wanting to stop smoking provided that the willpower is there. In other words, it will not do the job for you - you still have to do much of the hard work but acupuncture can make the effort that bit easier.
Treatment usually involves having needles inserted into the ear and sometimes other areas as well.