The effects of hot rolling and homogenisation treatment on the microstructure and mechanical properties of low-alloy transformation-induced plasticity (TRIP) steel were studied. With increasing the reduction in thickness during rolling, the band spacing and the average ferrite grain size decreased with the consequent enhancement of mechanical properties. Homogenisation treatment resulted in the gradual fading of the banded morphology, more homogeneous microhardness profile, and twice total elongation compared to the as-cast counterpart. The experimentally observed homogenisation time judged by the disappearance of the banded structure was in agreement with the obtained values based on the band spacing and elemental analysis. This work provided scientific evidence for the assumptions used to derive the homogenisation formulae.