Breast cancer is the most common cancer in women, according to the Cancer Registry of the Croatian Institute of Public Health in 2020 there was 2869 newly diagnosed women, which means that every eleventh woman in Croatia is at risk of developing breast cancer. It is thought that diagnosis of breast cancer causes greater psychological distress than any other diagnosis and research shows that cancer patients experience a higher frequency of stressful life events. As a result, stress-related factors reduce their overall ability to actively participate in the health treatment process and successfully fulfill daily activities. Due to the stated circumstances, the number of breast cancer patients who participate in complementary forms of therapy in addition to conventional treatment has been increasing in recent years. One of such approaches is mindfulness, which has shown its positive effects in alleviating physical and emotional difficulties associated with cancer and in reducing stress symptoms. Mindfulness approach is still insufficiently researched as a complementary method in treatment in the Republic of Croatia, so the aim of this review paper is to present the results of research on its possible effects on the mood and stress level in women with breast cancer all around the world, in order to contribute to awareness importance of focusing attention during difficult and unexpected life circumstances. In the mentioned researches were used only scientifically proven effective mindfulness methods and they showed more reduction in the anxiety, depression and stress levels in the experimental group compared to the control group.