Background: A cancer diagnosis can have a wide-ranging impact on mental health. Cancer patients usually experience high levels of psychological stress result in psychological distress symptoms such as anxiety. Cognitive behavioral therapy is one of the most evidence-based psychological interventions for the treatment of several psychiatric disorders such as anxiety. Aim: The purpose of this study is to explore the effect of cognitive behavioral nursing intervention program on anxiety among patients with cancer. Subjects and Method:  Design: A quazi- experimental design (pre, post, and follow-up evaluation) was used. Setting: Oncology unit at Al Shifa Medical Complex in Port Said city. Subjects: The study subjects included 63 patients with cancer. Tools: One tool were utilized to collect the data, Beck Anxiety Inventory; in addition to personal and clinical data sheet. Results: The study revealed nearly one third (35%) of studied patient with cancer had mild level of anxiety at pre intervention, while more than half (53.3%) of them had mild level of anxiety at post intervention. Also, half (50%) of the studied patients with cancer had moderate level of anxiety at pre intervention, while more than one third (36.7%) of them had moderate level of anxiety at post intervention. Conclusion: It was verified that, there are highly statistically significant relationship between levels of anxiety among the studied patients with cancer at pre- post nursing intervention. Recommendations: Cognitive behavioral nursing interventions should be utilized in combination with standard care for cancer treatment.