Background:Fatigue is the most common side effect of cancer treatment with chemotherapy and/or radiation therapy, selected biologic response modifiers. The main purpose of this study is to evaluate the effects of aerobic exercise on cancer-related fatigue in patients of the solid tumor after chemotherapy and radiotherapy.Methods:After screening for cancer-related fatigue, 34 patients fulfilled the inclusive criteria and were assigned into two groups (n = 17 recruited in the intervention group and n = 17 in control group). The intervention group received aerobic exercise program which included treadmill walking with low to moderate intensity (50%–70% of maximum heart rate), for 20–40 min/day for 5 days/week. Control group were taught stretching exercises of hamstrings, gastrocnemius, and soleus (to be done at home) and were encouraged to remain active. Outcome measures such as brief fatigue inventory (BFI), 6-min walk test, and functional assessment of cancer therapy-general (FACT-G) were taken at baseline and after 6-weeks.Results:The data were analyzed using the Wilcoxon matched-pairs signed rank test for within group and Mann–Whitney U-test for between group comparisons. The results of this study showed that there was a significant reduction in cancer-related fatigue BFI score (P < 0.0001,), also there was significant improvement in the physical performance as in 6-min walk distance (P < 0.0001) and quality of life, FACT-G score (P = 0.0001).Conclusion:Aerobic exercise for 6 weeks has beneficial effects on cancer-related fatigue in patients with solid tumor after chemotherapy and/or radiotherapy.