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In situ nano-SiC doped MgB 2 wires were fabricated from MgH 2 and B powders. Hydrostatic extrusion, followed by rotary swaging and two-axial rolling, were applied as the forming processes. The critical current J c of MgB 2 wires, made from MgH 2 and B powders, was significantly improved by nano-SiC doping. Nano-SiC doping substantially increased the upper critical (irreversibility) field B c2 above 20 T. The maximum J c values were measured for samples having 6 at.% SiC in low field and for those having 12 at.% SiC in high field, above 10 T. During the final sintering at 670 • C, the SiC decomposed and formed an Si-rich layer at the inner circumference of the Fe sheath. The composition of the core of SiC doped wires is more inhomogeneous in comparison to undoped ones, with MgO, Mg 2 Si and probably Mg 2 SiO 4 as the major segregated phases. Strong segregation of Si within the MgB 2 core was also observed. The highest T c−mid = 39.3 K was measured for undoped wire. For the optimal SiC doping amount ∼6 at.%, at high field, there was no difference in J c between hydrostatically extruded and hydrostatically extruded plus two-axially rolled wire. This can be attributed to the beneficial effect of hydrostatic extrusion, which causes higher density of the core in comparison to traditional deformation processes.