Thermal behaviour of cables can be predicted if their loading conditions and all the thermal parameters of the materials used in them are known. However, in practice these parameters are either difficult to obtain or can be subjected to slow variations due to aging effects. An alternative approach is proposed which involves solving an inverse problem of estimating the cable thermal parameters. A general solution procedure for the problem is developed, the principle of which is based on matching the computed thermal field to that obtained from experimental measurements. The method makes use of two basic techniques: the finite element method and a gradient-based optimisation method. To illustrate the procedure and its application, a practical case study is performed on the estimation of the thermal parameters of the 6.6 kV cables used for quayside cranes. The estimated parameters are then applied to the prediction of the temperature rise in cables.