Introduction: Antiphospholipid syndrome (APS) is an acquired autoimmune thrombophilia, characterized by vascular thrombosis or obstetric compromise, associated with the presence of antiphospholipid antibodies. Large international studies have analyzed the clinical/serological behavior of the disease and in Colombia, there are few cohorts that have been evaluated.Objective: The main objective is to characterize the patients with APS followed in the anticoagulation clinic of a tertiary care hospital and to determine the clinical manifestations and serological findings at diagnosis. Materials and methods: A retrospective descriptive study was carried out to evaluate patients with a presumptive and/or confirmed diagnosis of APS, according to modified Sapporo criteria, which fulfilled the inclusion and exclusion criteria established by the authors. The information was collected from the review of medical records.Results: We included 103 patients, with the female sex being the most prevalent (86.6%). 54.3% of the patients (n = 56) had a diagnosis of primary APS. Venous thrombotic events occurred in 87.3% (n = 90) of the patients, 34.9% (n = 36) had arterial thrombosis (n = 36), and 3.9% (n = 4) had catastrophic APS (n = 4). 15 cases of Obstetric APS were documented. Lupus coagulation inhibitor (LA) positivity was the most prevalent marker in 84% (n = 68) of cases.Conclusions: The clinical behavior in this cohort of patients is like that found in large international and national studies. Most patients have a probable diagnosis of APS, so they could overestimate the real prevalence and condition of long-term anticoagulant treatment.