Cs2LiYCl6 (CLYC) is a commercial scintillator material having good energy resolution and dual gamma/neutron detection capabilities. CLYC crystals currently used in detectors are grown by the vertical Bridgman method. Boules grown from stoichiometric melts, however, often contain secondary phases, Cs3YCl6 and LiCl, at the beginning and end of the crystal, respectively, suggesting that this composition is incongruently melting. Since no phase diagram containing CLYC existed in the literature prior to this study, the Cs2YCl5–LiCl phase diagram was explored. Several crystals were then grown from various melt compositions. As predicted from the phase diagram, a starting composition of around 60 mol% LiCl did not produce Cs3YCl6 and maintained a low concentration of LiCl.