BACKGROUND: There are no risk scores available for predicting heart failure in Type 2 diabetes mellitus (T2DM). Based on the Hong Kong Diabetes Registry, this study aimed to develop and validate a risk score for predicting heart failure that needs hospitalisation in T2DM. METHODS: 7067 Hong Kong Chinese diabetes patients without history of heart failure, and without history and clinical evidence of coronary heart disease at baseline were analyzed. The subjects have been followed up for a median period of 5.5 years. Data were randomly and evenly assigned to a training dataset and a test dataset. Sex-stratified Cox proportional hazard regression was used to obtain predictors of HF-related hospitalization in the training dataset. Calibration was assessed using Hosmer-Lemeshow test and discrimination was examined using the area under receiver's operating characteristic curve (aROC) in the test dataset. RESULTS: During the follow-up, 274 patients developed heart failure event/s that needed hospitalisation. Age, body mass index (BMI), spot urinary albumin to creatinine ratio (ACR), HbA1c, blood haemoglobin (Hb) at baseline and coronary heart disease during follow-up were predictors of HF-related hospitalization in the training dataset. HF-related hospitalization risk score = 0.0709 x age (year) + 0.0627 x BMI (kg/m2) + 0.1363 x HbA1c(%) + 0.9915 x Log10(1+ACR) (mg/mmol) - 0.3606 x Blood Hb(g/dL) + 0.8161 x CHD during follow-up (1 if yes). The 5-year probability of heart failure = 1-S0(5)EXP{0.9744 x (Risk Score - 2.3961)}. Where S0(5) = 0.9888 if male and 0.9809 if female. The predicted and observed 5-year probabilities of HF-related hospitalization were similar (p > 0.20) and the adjusted aROC was 0.920 for 5 years of follow-up. CONCLUSION: The risk score had adequate performance. Further validations in other cohorts of patients with T2DM are needed before clinical use.