Effects of alloying elements on sigma-related phase precipitation in super duplex stainless steels have been studied in detail, using transmission electron microscopy observation and hardness measurement. Increase in the ferrite stabilising element such as Cr, Mo, W increased the amount of sigma-related phase for a long ageing time, however for a shorter ageing time 2–3mass% W addition reduced the precipitation reaction rate of sigma-related phase. The role of W addition was clarified from the viewpoint of delaying effect on eutectoid decomposition of ferrite into sigma and austenite phases due to lower diffusion coefficient of W compared with Cr or Mo. It is also clarified that Mo is preferable than Cr to achieve super duplex stainless steel, considering the balance between pitting corrosion resistance and the susceptibility of sigma phase. Ni and N are known as the stabilising element for the austenite phase, so that the suppression of the sigma-related phase precipitation was expected. However N does not seem to change the precipitation susceptibility and Ni is clearly to accelerate the precipitation rate. The accelerating effect of Ni on sigma-related phase precipitation can be explained in terms of the reduction in the ferrite phase fraction resulting in the enrichment of sigma-related phase forming element in the ferrite phase. Moreover, from the standpoint of the suppression of sigma-related phase precipitation and the increasing corrosion resistance, the suitable chemical compositions of the super duplex stainless steels are also discussed.