In Japan, haemodialysis patients are required to adhere to a fairly rigid dietary regimen. Guided by Bandura’s theory of self-efficacy, this study tested a prediction model of dietary behaviour. A total of 325 individuals completed a self-administered survey containing nine scales, which were used to measure the six constructs in the model. Using multiple regression analysis, 24% of the variance on the Dietary Behaviour Scale could be accounted for by three predictor scales, Dietary Management Self-efficacy, Support from Family, and Self-Repressive Behaviour Patterns. Multiple regression analysis identified that four scales, Character Image of Dialysis Staff, Support from Family, Dialysis Acceptance, and Somatic Symptoms, contributed to 13% of the variance of the Dietary Management Self-efficacy Scale. These results might provide direction to those who are involved in the support and care of haemodialysis patients, some of whom require life-long treatment, as is common in Japan.