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-h ambulatory blood pressure monitoring in patients with high blood pressure belonging to a population with high cardiovascular risk.Methods: This study was descriptive, observational, and retrospective study, which analyzes 24-h outpatient pressure controls of 1858 patients, in Cartagena, Colombia.Results: One thousand one hundred and seventy-three examinations 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: Twenty-three-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.