A theoretical study of the NaC3 species has been carried out. There are three species lying quite close in energy: a linear isomer, 1d((2)Pi), a rhombic four-membered ring, 2d((2)A(1)), and a T-shape species, 3d((2)A(2)). The linear isomer seems to be the best candidate for the global minimum, although 2d and 3d are predicted to lie only 1.5 and 1.7 kcal/mol, respectively, higher in energy at the most reliable level of theory. Therefore these two species could also be accessible to experimental detection.