Mathematical analyses of wireless systems mostly consider fading and exclude the effect of shadowing since the derivation of performance metrics usually becomes extremely difficult. However, shadowing has to be studied to get better insights about the practical realisations. Therefore, generalised-K distribution has been widely used recently to model the impact of both fading and shadowing. In this study, the performance of popular maximal ratio transmission, which is a practical multiple antenna technique, is obtained for generalised-K fading channels. Particularly, outage probability, average channel capacity and symbol error rate expressions are derived and verified by computer simulations.