ABSTRACT: Smoking and withdrawal from smoking complicates the assessment and treatment of mental illness. We aimed to establish whether psychiatric inpatients smoke different amounts after admission than beforehand and, if so, to find out why. Forty-three inpatients on a working age adult psychiatry ward completed self-report questionnaires about smoking habits. Those who smoked a different amount after admission had a follow-up interview to find out why they thought this had occurred. The interview incorporated qualitative and quantitative aspects which were analysed accordingly.Fifty-six percent of participants were smokers before admission, rising to 70% afterwards. Of the smokers, 17% smoked less after admission, and 63% smoked more. The average number of cigarettes smoked per person per day increased from five to thirteen. The main reasons for smoking more were boredom, stress and the wish to socialise.