Cervical vertebrae are known from multiple specimens of "Neuquensaurus", although few are definitively associated with any other material. The centra are elongate, compressed vertically, and strongly , with an ovoid and rounded neural spine. Diagnostic of Saltasaurinae, the are shortened and robust and the extend far posteriorly to compensate. The lateral projections of the neural arch (transverse processes) are far more robust than in "Isisaurus". As in the cervicals, the dorsal vertebrae bear strongly opisthocoelous centra with lateral pneumatic openings. In the dorsals, however, the pleurocoels are posteriorly pinched and internally subdivided, a regular feature of titanosaurs. The pleurocoels of "Neuquensaurus" are proportionally taller than in "Trigonosaurus" or "Lirainosaurus". A ventral keel is lost throughout the dorsal series of probably 10 vertebrae, although the total count is uncertain. The vertebrae also lean less posteriorly towards the pelvis, initially inclined far beyond their individual centrum. However, they lack the of non-titanosaurs that limit vertebral motion. Two accessory are present in the dorsals of "Neuquensaurus" that are absent even in the close relatives "Saltasaurus" and "Rocasaurus". Unique among all sauropods, the sacrum of "Neuquensaurus" is composed of seven vertebrae. The last vertebra is convex anteriorly and posteriorly, and diagnostically the middle vertebrae are strongly compressed in width. Like other derived titanosaurs, all caudal vertebrae of "Neuquensaurus" are strongly and vertically compressed. There is a prominent ventral depression like in "Saltasaurus" and "Rocasaurus", but contrasting the other genera there is no ridge dividing this depression. Additionally, the neural spines of vertebrae become progressively more reclined, and a prespinal lamina is present in all vertebrae.