The research literature extensively indicates that prevalence rate of mental disorders in student population of Iran is high. In other hand, prevalence of suicidal ideation and attempt are reported high in students. The present research aims to study the relationship between depression and suicide in students of Guilan University. In a cross-sectional research, 71 students (13 students with history of suicide attempt, 17 students with depression diagnosis by psychiatrist and referring to counseling center of Guilan University, and 41 students without history of referring to counseling and psychiatric centers) were selected by convenience sampling from students of Guilan University. Beck Depression Inventory and Scale of Suicide Ideation were used for assessing depression and suicide thoughts, respectively. Statistical analysis by variance analysis showed that three group of subjects differed significantly (P< 0.01) in terms of score of depression and suicide thoughts: Depression average scores of depressed group (21.64) and attempting suicide (19.84) are more than students non-referring to counseling and psychiatric centers (8.75). In addition, the significant and positive correlation (P< 0.01) existed between suicide thoughts and depression in any three group of subjects. The powerful correlation exist between depression and suicidal ideation, and individuals with depressive symptoms are prone to, in addition to experiencing other problems due to depression, also think to suicide.