Objective To investigate the influence of self-care and self-efficacy intervention on the quality of life of patients undergoing chemotherapy after surgery for gastric cancer. Methods Sixty-four patients undergoing chemotherapy after gastric cancer surgery between July 2014 and February 2015 were selected as the study subjects. According the sequence of admission, they were divided into intervention group (n=34) and control group (n=30). Patients in the control group accepted conventional care, while those in the intervention group received self-efficacy and self-care interventions. The scores of General Self-efficacy Scale (GCES), Exercise of Self-care Agency (ESCA), and Quality of Life Instruments for Cancer Patients-Stomach Cancer (QLICP-ST) were compared between the two groups before and after intervention. Results After intervention, GCES scores of the intervention group and the control group were respectively (30.08±4.21) and (20.78±4.58) points; the total scores of ESCA were respectively (132.30±14.81) and (92.45±13.23) points; and the total scores of QLICP-ST were respectively (75.96±9.41) and (56.77±10.32) points. All the above differences between the two groups were significant (P<0.05). Conclusion Self-care and self-efficacy intervention can improve self-care ability and self-efficacy, and improve the quality of life of patients undergoing chemotherapy after gastric cancer surgery.