Factors associated with suboptimal interdialytic weight gain have long been established. However, the influence of cultural and linguistic diversity on interdialytic weight gain among patients receiving haemodialysis is not well-understood. This study examined the relationship between interdialytic weight gain and cultural and linguistic diversity among patients receiving haemodialysis. Retrospective cross-sectional study. Demographic and clinical data were collected from electronic medical records of patients receiving haemodialysis at five dialysis units. Logistic regression analysis was performed to determine factors associated with suboptimal interdialytic weight gain. Two hundred and sixty-nine patients, 62% of whom were female, with mean ± age of 65.8 ± 14.8 years, were studied. Most were from culturally and linguistically diverse backgrounds (60%) and a significant number belonged to the most disadvantaged socioeconomic group. Patients from culturally and linguistically diverse backgrounds had significantly higher relative interdialytic weight gain (2.40% ± 1.45%) compared to those from nonculturally and linguistically diverse backgrounds (1.83 ± 1.09%) (mean difference: 0.57%, 95% CI: 0.25-0.90, p = 0.001). Being from culturally and linguistically diverse backgrounds was associated with increased odds of higher relative interdialytic weight gain (OR: 2.40; 95% CI: 1.38-4.17, p < 0.01). Among patients on maintenance haemodialysis, individuals from culturally and linguistically diverse backgrounds had higher interdialytic weight gain compared to those from nonculturally and linguistically diverse backgrounds. Future research focusing on co-developing culturally sensitive interventions to improve self-management capability of patients on maintenance haemodialysis from culturally and linguistically diverse backgrounds is needed.