Background: Medical treatment for eliminating the side effects of cancer therapy may not always be efficacious. Acupuncture is one of the most widely accepted alternative and complementary therapies in use today. In this study, we investigated the efficacy of acupuncture in patients experiencing cancer treatment side effects, including nausea, vomiting, pain, poor sleep quality and anxiety. Materials and Methods: A total of 45 inpatients who underwent chemotherapy between February and April 2013 in the Oncology Department of Numune Hospital were included in our study. Acupuncture was administered to the patients one day prior to chemotherapy, on the day of chemotherapy and one day after chemotherapy. The patients were evaluated on nausea, vomiting, pain, sleep quality and anxiety before the chemotherapy and on the $4^{th}$ day of chemotherapy. Results: Of the 45 patients included in the study, 18 (40%) were female and 27 (60%) were male. A total of 25 (55.6%) had an elementary school education; 32 patients (71%) had stage 4 cancer and were treated with palliative chemotherapy (the patient characteristics are shown in Table 1). Statistically significant decreases (p<0.001) in pain, nausea, vomiting, insomnia and anxiety scores were observed after the acupuncture treatment compared to baseline. There were no differences in the age, gender, education level, stage or metastasis levels between the patient groups whose symptoms improved or were unchanged. Conclusions: Our study showed that acupuncture has positive effects in cancer treatment patients who experience nausea, vomiting, pain, poor sleep quality and anxiety as side effects of chemotherapy. Chemotherapy-related side effects in cancer patients could be decreased by the concurrent use of acupuncture.