The incidence of diabetes mellitus (DM) has escalated in recent decades, and the risk of diabetes-related mortality has increased dramatically due to the co-existence of hypertension (HTN). DM and HTN, having similar aetiology and disease mechanisms, are influenced by lifestyle factors and greatly contribute to critical health complications. This study attempted to explore the co-existence of DM–HTN and the potential determinants considering the rapid upsurge of both these diseases. National Family Health Survey data were used, which included 7092 adult diabetic individuals, to find out the prevalence rate of HTN in diabetic persons in India. Appropriate statistical analyses were performed to accomplish the study objectives. Prevalence rate of HTN in diabetic individuals was approximately 37%. Higher body mass index (BMI) was associated with DM–HTN co-existence. In males, increased age, higher BMI, alcohol consumption, poorest wealth index, and non-smoking (tobacco) were the significant determinants of the co-existence of DM-HTN, while in females, they were increased age, higher BMI, and geographical region. This study unveiled the significance of healthy lifestyle maintenance and equitable health care services to prevent HTN among diabetics, along with promotion of the awareness and management of DM and HTN through appropriate pharmacological treatments. [ABSTRACT FROM AUTHOR]