The holotype and only known specimen of Agustinia, MCF-PVPH-110, was discovered in 1997 by an expedition from the Museo Argentino de Ciencias Naturales in Buenos Aires, a few kilometers west of the city of Picún Leufú in the south of the Neuquén province.

[1] The generic name Agustinia honors then-student Agustin Martinelli, who discovered the skeleton and was part of the excavation team of the Museo Argentino de Ciencias Naturales.

[2] The specific name, ligabuei, honors Dr. Giancarlo Ligabue, a philanthropist who provided financial support to the expedition which recovered the remains.

[4] Further study of the poorly preserved fossil material showed that these "plates" were in fact more likely to be fragments of ribs and hip bones.

Because of this, some authors have considered Agustinia a nomen dubium for being based on inadequate remains to compare with related dinosaurs.

[8][5] In contrast, D'emic et al (2009) concluded that no diagnostic features were present that would allow a classification within the Diplodocoidea or Titanosauria, and therefore classified Agustinia as Neosauropoda incertae sedis.

[4] A 2022 publication by Flavio Bellardini et al. found sufficient evidence to classify Agustinia as a rebbachisaurid within the Diplodocoidea, more derived than Amazonsaurus.