Hot rolling of steel is an energy-intensive process, in particular with respect to pre-heating of the steel slabs. The present work was carried out with the aim of reducing the initial slab temperature while at the same time improving properties by optimisation of the steel composition and process parameters. Optimisation of slab reheating and hot rolling parameters in connection with heavy plate rolling has been carried out for high strength microalloyed steels in laboratory scale processing. The investigation has been focussed on ~0.15%C-~1.1%Mn steel with and without Mo and microalloyed with Ti-B or Al-Nb-B. Effects of low slab reheating temperature, finish rolling temperature during thermo-mechanical control processing (TMCP) and accelerated cooling rates (ACR of 20-60°C/s) following hot rolling to RT have been investigated. The results obtained in laboratory scale for the TMCP simulation of plate show that the low reheating temperature of 1150°C combined with high applied finish rolling temperatures and cooling rates over 20°C/s are good TMCP parameters for production of heavy plate with very good mechanical properties for the present steels. Lowering the slab reheat temperature reduces energy consumption and in this way releases less CO2 into the atmosphere during the thermo-mechanical processing of the present steels.