This study was a randomised controlled trial designed to assess the effectiveness of progressive muscle relaxation training (PMRT) in the clinical management of chemotherapy-related nausea and vomiting as an adjuvant intervention to accompany pharmacological antiemetic treatment (metoclopramide and dexamethasone i.v.). Seventy-one chemotherapy-naive breast cancer patients of an outpatient oncology unit of a university hospital in Hong Kong participated, with 38 subjects randomised to the experimental group and 33 to the control group. The intervention included the use of PMRT 1 h before chemotherapy was administered and daily thereafter for another 5 days (for a total of six PMRT sessions). Each session lasted for 25 min and was followed by 5 min of imagery techniques. The instruments used for data collection included the Chinese versions of the Profile of Mood States and the State-Trait Anxiety Inventory (measured before chemotherapy and then at day 7 and day 14 after chemotherapy), and the Morrow Assessment of Nausea and Vomiting Scale, which was used daily for the first 7 post-chemotherapy days. The use of PMRT considerably decreased the duration of nausea and vomiting in the experimental group compared with the control group ( P<0.05), whereas there were trends toward a lower frequency of nausea and vomiting ( P=0.07 and P=0.08 respectively). Neither nausea nor vomiting differed in intensity between the two groups. The significant effects were mainly evident on the first 4 post-chemotherapy days, when differences were statistically significant. Although there was a significantly less severe overall mood disturbance in the experimental group over time ( P<0.05), this did not apply in the case of anxiety. Such findings suggest that PMRT is a useful adjuvant technique to complement antiemetics for chemotherapy-induced nausea and vomiting and that incorporation of such interventions in the care plan can enhance the standards of care of cancer patients who experience side effects of chemotherapy.