Autism spectrum disorder presents as a multifaceted condition characterized by pronounced impairments in social communication and behavioral patterns. Diagnosis hinges upon the expertise of clinicians, comprehensive developmental history, and observation of specific behavioral markers. However, in low-income countries, access to screening tools and standardized diagnostic tests for autism spectrum disorder remains profoundly limited. Moreover, the COVID-19 pandemic has exacerbated these challenges, rendering diagnostic protocols impractical. In response to these barriers, the Brief Observation of Symptoms of Autism instrument was developed to facilitate assessments via telehealth during the pandemic. This study aims to validate the use of the Brief Observation of Symptoms of Autism within two Latin American countries, Argentina, and Chile. A cohort of 313 spanning various age groups underwent examination. Psychometric properties of each Brief Observation of Symptoms of Autism module were scrutinized, including sensitivity and specificity against the recommended University of California at Los Angeles cutoffs. Receiver operating characteristic curve analysis yielded credible sensitivity and specificity scores for each module. Confirmatory factor analysis supported a favorable fit across modules, employing a 2-factor model distinguishing Social Affect and Restricted, Repetitive Behaviors. Preliminary findings affirm the validity of the Brief Observation of Symptoms of Autism as an effective diagnostic tool within the Latin American population. Furthermore, its potential extends beyond the pandemic, promising support in the future.