MnSi and MnSi2-x single crystals were grown from high temperature gallium metal fluxes by slowly cooling the melt in argon atmosphere. The growth conditions of MnSi and MnSi2-x (Mn15Si26) crystals with relatively large size, namely MnSi about 0.06 x 0.52 x 2.43 mm(3) and Mn15Si26 about 0.40 x 0.55 x 0.61 mm(3) were established. MnSi crystals were generally obtained in the form of needle-like prisms extending in the <1 0 0 > direction and with well-developed (1 1 1) faces. Mn15Si26 crystals had a nearly spherical polyhedral shape, greyish color and metallic luster. The as-grown MnSi and Mn15Si26 crystals were used for chemical analyses and measurements of unit cell parameters. Vickers microhardness was determined on MnSi and Mn15Si26 crystals, and oxidation at high temperature in air was studied for MnSi and Mn15Si26 crystals.