Neurosporene is a carotene and an intermediate in the synthesis of lycopene from phytoene. Its content in carotenogenic organisms is very low; hence, the complete assignments of its spectroscopic data, including NMR, are insufficient. A purple bacterium of Rhodobacter sphaeroides G1C mutant had only one carotenoid. This carotenoid was extracted and purified using silica gel, DEAE-Toyopearl and C-18-HPLC columns. It was identified using its absorption spectra, mass spectra, and H-1- and C-13-NMR spectra, including two-dimensional spectral analyses. The major carotenoid in the Rhodobacter sphaeroides G1C mutant was identified as neurosporene (7,8-dihydro-psi,psi-carotene) using spectroscopic measurements, including complete assignments of its H-1- and C-13-NMR spectral data.