Background: High blood pressure is considered a disease and at the same time a cardiovascular risk factor, mainly involved in ischemic heart disease, cerebrovascular disease and kidney failure, causing high mortality worldwide. Objective: The objective was to follow up with 24-hour ambulatory blood pressure monitoring in patients with high blood pressure belonging to a population with high cardiovascular risk. Method: Descriptive, observational, retrospective study, which analyzes 24-hour outpatient pressure controls of 1858 patients, in Cartagena, Colombia. Results: 1173 exams were validated and included in the study. The median age was 66 years. 66.8% (783) were women and 33.2% (390) were men. The main changes occurred during the night, when 79.1% of the patients had high systolic pressure loads, 65.6% recorded diastolic pressure averages and 83.7% had abnormal circadian patterns. Only 11% of the studies were normal in all parameters. Conclusions: 24-hour ambulatory blood pressure monitoring proved to be a useful tool to identify uncontrolled hypertensive patients, detect nocturnal hypertension and abnormal circadian patterns, which are risk markers for cardiovascular morbidity and mortality.