Background: Cancer is one of the major health issues worldwide. An increasing number of cancer patients are offered treatment with surgery, chemotherapy and radiotherapy. Traditional Chinese medicine (TCM) is one of the most common complementary therapies offered to cancer patients in Taiwan. We designed a randomized, double-blind, placebo-controlled clinical trial to evaluate the efficacy of TCM in patients with cancer., Methods/design: In this study, inclusion criteria are postoperative patients with histologically confirmed cancer within 3 years who are undergoing chemotherapy or radiotherapy, more than 18 years old, have given signed informed consent, have the ability to read Chinese, and the ability for oral intake.Exclusion criteria include being pregnant, breast feeding, having completed chemotherapy or radiotherapy, brain metastasis with Eastern Cooperative Oncology Group (ECOG) performance status of two to four, delusion or hallucinations, acute infection, and have received medications under other clinical trials.The patients were separated into an intervention group (Shen-Mai-San, SMS) and a placebo group for four weeks using a randomized, double-blind procedure. The European Organization for Research and Treatment of Cancer (EORTC) Quality of Life questionnaire (QOL-C30) was used to evaluate the quality of life. General data, hemoglobin (Hb), hematocrit (Hct), glutamic-oxalacetic transaminase (GOT), glutamic-pyruvic transaminase (GPT), blood urea nitrogen (BUN), creatinine, carcinoembryonic antigen (CEA), TCM diagnosis data and heart rate variability (HRV) were also recorded. These data were collected at baseline, two weeks and four weeks after receiving medication. The patients were prescribed granules which contained therapeutic medicines or placebo. Paired-T test was used for statistical analysis., Discussion: Shen-Mai-San is composed of processed Ginseng radis, Liriope spicata, and Schizandrae fructus. It was found to be effective for treating cancer-related fatigue and had anti-fatigue activity. In TCM theory, SMS has a synergistic effect for qi and yin deficiency and has the ability to prevent fatigue. The symptoms of qi and yin deficiency are similar to chemotherapy- or radiotherapy-induced side effects. In order to evaluate the efficacy of SMS on cancer treatment, we designed a randomized, double-blind, placebo-controlled trial., Trial Registration: This study is registered to Clinical Trails.gov NCT01580358.