Introduction:
Cigarette smoking is the single largest preventable cause of death and disability in the industrialized world and it causes at least 85% of lung cancers, chronic bronchitis and emphysema. In addition smokers are at a higher risk from psychiatric co-morbid illness such as depression and completed suicide.

Methods:
We conducted a cross-sectional survey in which we targeted all patients with serious mental illness (SMI) who were admitted in Razi mental health Hospital in Tehran, Iran. We recruited 984 participants, who were receiving services from Razi mental health Hospital and hospitalized for at least two days between 21 July to 21 September, 2010. Nine hundred and fifty patients out of this figure were able to participate in our study.

Results:
The final study sample (n = 950) consisted of 73.2% males and 26.8% females. The mean age was 45.31 (SD=13.7). A majority of participants (70%) was smoker. A history of never smoking was present for 25.2% of the study sample; while 4.8% qualified as former smokers and 70.0% as occasional or current smokers. Two hundred and nineteen participants had attempted suicide amongst them 102 (46.6%) once, 37 (16.9%) twice, and 80 (36.5%) attempted more than two times in their life time. In regression model, gender, age, and cigarette consumption were associated with previous suicide attempts and entered the model in this order as significant predictors.

Conclusions:
There is an association of cigarette smoking and suicide attempt in psychiatric inpatients. Current smoking, a simple clinical assessment, should trigger greater attention by clinicians to potential suicidality and become part of a comprehensive assessment of suicide risk.