This article will describe suicidal thoughts in cancer, prevalence rates, risk factors, and will provide clinical model for monitoring and intervention among cancer patients with mixed anxiety-depression disorder (MADD). A total of 187 spouses of cancer patients attending oncology clinics of two hospitals in Tehran, Iran, participated in the research program. Spouses completed the Beck Depression Inventory (BDI), which included Item 9 that asks patients if they have had suicidal thoughts or wishes in some way in the previous 2 weeks. Also, the spouse is given the Automatic Thought Record (ATR) and asked to recall the suicidal thoughts he had together with the situation in which they occurred and the emotion felt. The prevalence of positive responders was calculated. Overall, 11.2% (21 of 187) of spouses were positive responders to Item 9, which indicated that they had suicidal thoughts. The associations of a positive response with the following variables were analyzed by using Multivariate Logistic Regression with the method of stepwise selection: anxiety, depression, mixed anxiety-depression disorder (MADD) and normal spouses. Clinically significant depression (β = -.182; P < .05) and MADD (β = .511; P <
.05) were strongly associated with a positive response, and anxiety (β = -17.62; P < .05) was weakly associated. Findings showed that cognitive declines were associated with suicidal ideation in spouses of cancer patients. Spouses of women with cancer who are depressed or MADD are often stuck in repetitive suicidal thoughts which they cannot re-evaluate. When depression and cancer are combined, suicidal thoughts may be exacerbated.