Cancer is the leading cause of death worldwide. Its treatment consists of surgical therapy, chemotherapy, radiotherapy, and hormonal therapy, alone or in combination. Among these, chemotherapy causes the most physical changes. The study aimed to assess the effectiveness of Mandala therapy on nausea, pain and distress among patients with cancer receiving chemotherapy. A true experimental research design was carried out among 80 patients (randomised to 40 each in the control and experimental group), selected by a consecutive sampling technique in a selected tertiary care centre. The baseline characteristics were assessed using pre-tested and pre-determined tools such as demographic variables proforma, clinical variables proforma, nausea and vomiting tool, numerical pain rating scale and distress thermometer in both the groups. After the pre-test, mandala therapy was given to the experimental group of patients after 1 hour of starting the chemotherapy for 2-3 hours. Immediately after the intervention, post-test assessment of nausea, pain and distress was done in both the groups with the same tool. The collected data were analysed by using descriptive and inferential statistics. The study findings showed that there was a significant difference in post-test pain and distress (0.65 and 0.72) than the control group at p<0.005 level, without any changes in the nausea score indicating that Mandala therapy is effective in reducing pain and distress among patients with cancer receiving chemotherapy.