Introduction: arterial hypertension (AHT) can debut with a hypertensive crisis (HC), whose prevalence is 1-2%.These crises are classified as urgencies (HUs), emergencies (HEs) or pseudocrises (HPs).Objective: to determine the clinical characterization and identification of factors associated with HC in the emergency room.Materials and method: This was an analytical cross-sectional study based on records of patients ≥ 18 years old who were seen in the emergency room between 2020 and 2021 with blood pressures (BP) ≥ 180/120 mmHg and a confirmed diagnosis of HC.Prevalences were estimated, and odds ratio and logistic regression models were calculated, with confidence levels of 95%.Results: the prevalence of HC was 1.7%, 59.4% were women aged 66.34 ± 13.8 years, and 88.7% had a history of hypertension.The most frequent chronic treatment was angiotensin II receptor blockers (ARBs) (52.9%).The most common HC was HE (54.6%).Blood pressure levels were higher in the HE group (p < 0.001).Headache was the most frequent symptom (30.0%).Chronic use of angiotensin-converting enzyme (ACE) inhibitors was associated with a lower probability of presenting with HE (68%).Chronic kidney disease was associated with an increased probability of HU (OR = 2.77; 95% CI = 1.31-5.87);coronary heart disease and cerebrovascular disease with an increased probability of HE (OR = 3.11).95% CI = 1.15-8.45and OR = 4.4; 95% CI = 1.69-11.58).The most used therapy for HU and HP was losartan (47.56% and 43.14%), and for HE was labetalol (48.75%).Conclusions: Knowing the frequency and association of HC helps improve the medical assessment, use of tests, treatment and prognosis.