The reliability of strained Si devices on several technology platforms has been investigated, highlighting the advantages and disadvantages in each case. The devices had biaxial strain induced through the use of a SiGe strain relaxed buffer or uniaxial strain induced through the use of strained nitride liners or stress memorisation. Since there is much literature demonstrating the benefits of using strain engineering to enhance drive current and speed, the aim of this thesis has been to present several aspects of device reliability that have not been studied previously and to demonstrate the need for significantly more research.