Photoluminescence (PL) has been observed at room temperature from a Ga0.96In0.04As0.11Sb0.89 quaternary solid solution for the first time. High-quality epitaxial layers of n-type (Te-doped) Ga0.96In0.04As0.11Sb0.89 with low In content were grown by liquid phase epitaxy (LPE) lattice-matched to InAs(100) substrates from a Ga-rich melt. The PL properties of the material were investigated over a wide temperature range, and the principal radiative transitions were identified. In the temperature range <150 K, donor-acceptor recombination involving the first and second ionization state of native antisite defects was the dominant radiative-recombination process, whereas interband recombination was found to dominate at room temperature.