Hypertension is a chronic disease in the elderly that requires a special sustainable diet management pattern. This study aims to determine the relationship between knowledge and adherence to a special diet for high blood pressure in the elderly group. The research design used a cross sectional with a correlational approach using chi-square analysis. A sample of 30 elderly people was selected using the convenience sampling method. The results showed that there was a significant relationship between knowledge and adherence to a special hypertension diet (p= 0.003). The majority of the elderly have knowledge about hypertension in the good and sufficient range, with adherence to a special diet for high blood pressure at moderate and high levels. The provision of health education related to the characteristics of the elderly is needed in increasing the knowledge and diet adherence on the elder population. Â