A great variety of clinical and immunological features have been described in patients with the antiphospholipid syndrome (APS), but information on their prevalence and characteristics in Latin American mestizo patients with the primary APS is scarce. To analyze the prevalence and characteristics of the main clinical and immunological manifestations in a cohort of patients with primary APS of mestizo origin from Latin America and to compare them with the European white patients, clinical and serological characteristics of 100 patients with primary APS from Colombia, Mexico, and Ecuador were collected in a protocol form that was identical to that used to study the "Euro-Phospholipid" cohort. The cohort consisted of 92 female patients (92.0%) and eight (8.0%) male patients. They were all mestizos. The most common manifestations were deep vein thrombosis (DVT; 23.0%), livedo reticularis (18.0%), migraine (18.0%), and stroke (18.0%). The most common pregnancy morbidity was early pregnancy losses (54.1% of pregnancies). Several clinical manifestations were more prevalent in the Latin American mestizo than in the European patients (transient global amnesia, pulmonary microthrombosis, arthralgias, and early pregnancy losses) and vice-versa (DVT, stroke, pulmonary embolism, and thrombocytopenia). Latin American mestizo patients with primary APS have a wide variety of clinical and immunological manifestations with several differences in their prevalence in comparison with European white patients.