Efficient contactless power transfer (CPT) is an emerging technology which is attracting great scientific interest because it can mitigate some of the problems commonly associated with conventional wired power transfer systems. CPT systems suffer from very low efficiency because of the poor coupling coefficient, which is due to the large air gap between the transmitter and receiver coils. Therefore, CPT transformers are mostly operated at high frequencies to improve the quality factor of transmitter and receiver coils and thus counterbalance the effect of the low coupling coefficient. On the other hand, informed selection and design of core materials for CPT transformers can improve the coupling coefficient and thereby boost the overall power transfer efficiency of the system. However, at high power and high frequency CPT applications, core losses become very high and play an important role in determining the efficiency of the system. This paper reports on a detailed investigation into the suitability of nanocrystallines as core materials for high power and high frequency CPT systems.