Hypertension was a major public health problem worldwide and was the most common risk factor for cardiovascular disease, so it was called the silent killer, and had not been optimally controlled worldwide. Lack of patient knowledge causes low compliance in taking drugs in hypertensive patients. The purpose of this study was to determine the relationship between knowledge and adherence to medication in hypertensive patients. This research design uses correlation analytic with cross sectional approach. The population in this study wasall hypertensive patients in Mojolegi Hamlet, Sawo Village, Work Area of the Pesanggrahan Health Center, Mojokerto Regency, with a total of 40 people. The sampling technique of this research was total sampling. The sample in this study amounted to 40 people. The research instrument used a Hypertension Knowledge Level Scale and Hill Bone questionnaire. Data analysis used crosstab. The results showed that almost half of the respondents had good knowledge, were obedient in taking medicine, as many as 17 respondents (42.5%), respondents who had good knowledge, but were not compliant in taking medicine, as many as 2 respondents (5%), respondents who had sufficient knowledge. , and were obedient in taking medication, as many as 4 respondents (10%), respondents who had sufficient knowledge and were not obedient in taking medication, as many as 13 respondents (32.5%). The results of crosstab analysis show that respondents who had good knowledge tend to be obedient in taking drugs. Respondents who had good knowledge, they wpuld be obedient in taking drugs because knowledge was the basic for a person to act so the action would be long lasting. Respondents who knew that hypertension drugs must be taken every day would tend to comply.