The objective of this study was to examine the relationship between subjective symptoms of inadequacy of methadone dose (not feeling "held") and tobacco smoking in patients in methadone maintenance treatment (MMT). This was a cross-sectional study of smoking behaviour, investigating subjective, physiological and psychological symptoms. The study took place in a community-based methadone maintenance clinic of a psychiatric teaching hospital in South London. Fifty adult opiate addicts (37 males and 13 females) were on a stable daily methadone dose; the number of cigarettes smoked during the day and previous day of investigation, salivary cotinine measurements and carbon monoxide (CO) from expired air were measured. The Methadone Symptom Checklist (MSC) was used to score withdrawal symptoms encountered in patients not feeling "held" during MMT The Hamilton Anxiety Score was also used. The prevalence of tobacco-smoking was high (98%), with two-thirds (68%) smoking self-fabricated cigarettes ("roll-ups"). Scores from rating scales measuring symptoms of not being "held" correlated with number of cigarettes smoked the previous day (p < 0.05). A similar correlation was found with the Hamilton Anxiety Score. However, there was no correlation between rating scale scores and either salivary cotinine concentration or CO from expired air. Methadone patients who smoke more are significantly more likely to report problems of not feeling "held" by their methadone dose and they also show a higher level of anxiety. However, this increased cigarette consumption is not reflected in increased salivary continine levels or levels of CO in expired air, and it may be that the raised level of anxiety leads to a smoking-pattern consisting of frequent lighting-up of cigarettes or "roll-ups" which are consumed incompletely and/or not smoked by inhalation.