Background: Cancer is one of the most important health problems, which cause anxiety. Owing to physical and psychological problems it may lead to thinking about impending death. Logotherapy is the most powerful method to treat problems that exist in nature. Objectives: This study aimed to determine the effect of group logotherapy on spirituality and death anxiety in patients with cancer. Methods: This randomized clinical trial study was done on patients with cancer referred to Imam Khomeini Hospital in Sari in 2017. Sixty-four eligible patients were selected from the oncology clinic using convenience sampling method. Patients were randomly allocated to the control and intervention groups (n = 32). Group logotherapy was done for the intervention group for five weeks. Data was gathered through a questionnaire, including demographic, Templer Death Anxiety Scale (DAS), and Spirituality Questionnaire (SQ) one week before and one week after the intervention. Data were analyzed in SPSS V. 16 software using independent t-test, Wilcoxon, and Mann-Whitney U test. The significant level was considered 0.05. Results: There were no significant differences in death anxiety and spirituality scores between the two groups at baseline, indicating that the two groups were matched in terms of death anxiety and spirituality. Before the logotherapy, the mean score of death anxiety in both groups was high (more than 8). After the logotherapy, the mean and SD of death anxiety score in the intervention and control groups were 7.14 ± 4.12 and 9.76 ± 2.64, respectively, there were statistically significant differences in death anxiety scores between the groups (P < 0.05). There were statistically significant differences between the mean of spirituality score in the intervention group before and after the logotherapy (P < 0.05), but it was not significant in the control group, indicating that group logotherapy was effective in increasing the spirituality score. Conclusions: Based on the findings, group logotherapy can increase the spirituality score of the patients. Moreover, the logotherapy may result in decreasing death anxiety, and spirituality-oriented meetings may be beneficial for patients.