LiMnPO4 crystals with orthorhombic Prima crystal structure containing large grains have been grown successfully for the first time by the traveling-solvent floating-zone technique under elevated argon pressure. The grains achieve sizes of about 3 mm(2) x 10 mm and display an orange transparent color. During the growth process, the traveling zone is continuously enriched with PO4- and Li-ions, due to the self-adjustment of the liquid zone, which hinders grain selection and leads to constitutional supercooling with the formation of a secondary phase in a later stage of the process. Magnetic measurements performed on oriented cuboids reveal antiferromagnetic ordering of the Mn2+-ions below T-N approximate to 34 K. The c-axis is the easy magnetic axis. (C) 2009 Elsevier B.V. All rights reserved.