A key tool in quality assurance programs in radiotherapy is dosimetric auditing. This study evaluated the feasibility of implementing, for the first time in Argentina, a postal dosimetric audit program for high dose rate brachytherapy (HDR-BT) using an Ir-192 source and optically stimulated luminescence dosimeters (OSLDs). A solid phantom measuring 8 × 14 × 8 cm3 was designed and built, featuring channels for the source and a compartment for a nanoDot OSLD. The dosimeters were characterized and calibrated using a Gammamed Plus iX unit equipped with an Ir-192 source, and influence factors affecting dose measurements, as well as potential protocol deviations, were assessed. A pilot study was conducted in collaboration with three radiotherapy centers in the country. The phantom proved to be durable for postal delivery, practical, and cost-effective. The OSLD characterization was satisfactory, with influence factors within internationally accepted ranges. The total uncertainty of the system was ± 4% (95% confidence level), allowing an acceptance criterion of ± 5% for percentage deviations between the dose reported by the center’s treatment planning system (TPS) and the dose measured with OSLDs. All three results were within the established acceptance limit, regardless of the HDR-BT equipment used. This initial experience yielded very promising results and lays the foundation for a future national dosimetric audit program in HDR brachytherapy.