Improving the user performance is one of the major issues in the Brain-Computer Interface (BCI) field. In this study, the following question is asked: can hypnosis enhance the performance of motor imagery based BCI? Indeed , hypnotic inductions using Ericksonian suggestions can make the user feel simultaneously more relaxed and more focused on the mental task, and therefore could be used to increase performance in BCI. The aim of this study was to evaluate the impact of an hypnotic condition on the ERD/ERS patterns during a kinesthetic motor imagery (KMI) task. To investigate this issue, 19 right-handed healthy subjects performed a KMI of the right hand during two randomized sessions: in normal and hypnotic conditions. We analyzed the event-related (De)-synchronization (ERD/ERS) over the motor cortex and compared the BCI accuracy during both conditions. Our results suggest that the state of hypnosis reduces the ERD phase in the sensorimotor bands, assuming a change in the activation of the motor cortex during the hypnotized state and thus a worst detection of the kinesthetic motor imagery.