The diagnosis of cancer is a traumatic experience, which may result in post-traumatic stress symptoms, such as arousal, re-experiencing the diagnostic process and avoidance. Changes in post-traumatic symptoms were assessed in 181women with breast cancer who participated in either a standard support group or complementary/alternative (CAM) oriented intervention. At baseline 26 women were classified as having significant PTSD symptoms. After the 12-week sessions, significant decreases in the number of women with PTSD was seen in both interventions, however it was more evident in the Standard group where there was a 91% reduction in the number of women with PTSD versus an 80% reduction in the CAM group. For women with PTSD both groups showed significant decreases in overall PTSD symptoms and arousal. However, only the women in the Standard support group showed significant decreases in re-experiencing and avoidance symptoms. For the entire sample only women in the Standard group had significant decreases in overall PTSD, re-experiencing, and arousal. These results indicate that PTSD symptoms can be prevalent among women with breast cancer, and that while psychosocial interventions can be effective in reducing this type of distress, a support group might be more effective than a more complementary/alternative oriented intervention. Copyright © 2005 John Wiley & Sons, Ltd.