Abstract Introduction Cancer is the most leading cause of death globally. Fatigue and poor quality of sleep are the common side effects of cancer treatment that lead to poor quality of life. There is a need of complementary therapy, which can help to minimize the side effects of cancer treatment and boosting relaxation. Warm water foot submerged technique helps to relieve fatigue and improve the quality of sleep; hence, quality of life can be improved. This study was conducted to assess effectiveness of warm water foot submerged technique on the level of fatigue, quality of sleep, and quality of life among patients with cancer. Materials and Methods A quasi-experimental pretest and post-test control group research design was adopted to conduct the study in oncology ward of selected hospital. Sixty-eight participants were recruited using a nonprobability purposive sampling technique and allocated to intervention and control groups. Data was collected using multidimensional fatigue inventory, Groningen sleep quality scale, EORTC QLQ-C30. The control group received normal routine care and the intervention group received warm water foot submerged technique that was given for 15 minutes two times per day for 5 consecutive days. Results Warm water foot submerged technique showed a significant difference in level of fatigue (p < 0.05), quality of sleep (p < 0.001), and quality of life (p < 0.001) in the intervention group. There was no significant difference in control group. Conclusion This study showed that the warm water foot submerged technique is effective in reducing the fatigue and improving the quality of sleep and quality of life among patients with cancer. Thus, this study was found to be effective.