Background and Aim: Thalassemia major is one of the most common chronic genetic diseases in the world and in Iran that can impose many adverse effects on the self and society. Psychologically, patients with thalassemia are under stress. According to the World Health Organization (WHO), suicide is one of the leading causes of death worldwide. It is important to identify the people who have the highest risk factors for suicide. The present research investigates the frequency of thoughts, readiness and suicide attempts in people with thalassemia. Methods: This was a cross-sectional study. Its sample was 150 patients with thalassemia in the age range of 10 to 46 years whom we selected through census by sampling at convenience. We gave to patients a standardized Beck Suicide Thought Assessment Questionnaire. We analyzed the research data using descriptive and inferential statistical tests. Results: From among 150 patients with thalassemia in this study, 57.3% of the respondents were male and 42.7% were female. The results showed that there was a negative and significant relationship between suicide thoughts and attempts and age (-0.234) (P <0.05). The mean prevalence of suicide in men (1.89) was significantly higher compared to women (0.79) (P <0.05). We did not observe significant difference in prevalence of suicide thoughts and attempts between married and single groups with a mean difference (0.69) (P <0.05) and, in different educational groups, no significant difference was reported (P> 0.05). Conclusion: The findings of this research showed that among patients with thalassemia, the prevalence of suicidal ideation has a significant percentage. Since suicidal ideation provides a platform for preparation and attempt to commit suicide, so by providing mental health services and regular screening, we can take an effective step to prevent this problem among patients with thalassemia. Keywords: Thalassemia, Suicidal ideation, Suicide.