We report the occurrence of important carbon isotope excursions in early Paleozoic formations of the Eastern and Central Argentine Precordillera. The Steptoean positive isotope carbon excursion (SPICE) is known from North America, Kazakhstan, South China, Australia and South America, and the negative isotope carbon excursion (SNICE) has been described for the first time in South America. We report here the record of the SPICE and SNICE in a single section in the Eastern Precordillera. In the Central Precordillera, a minor middle Darriwilian positive carbon isotope excursion (MDICE) and a late Sandbian positive isotope carbon excursion, the GICE (~ + 3‰; C. bicornis biozone) are reported from two sections. One pre-GICE positive carbon-isotope excursion (Sandbian Sa1, N. gracilis biozone) in the Central Precordillera with a δ13C peak of ~ + 2‰ is, perhaps, equivalent to the positive Spechts Ferry δ13C excursion of North America. A positive δ13C excursion (~ 6‰; N. persculptus biozone) recorded at the base of the late Hirnantian La Chilca Formation probably corresponds to HICE