The present study aimed to determine the frequency of possible associationbetween CIDP & CNS involvement, & to correlate the clinical, Neurophysiologicalfindings with possible association. 40 adult Egyptian patients (20 males & females)diagnosed as having CIDP were included in this study & were subjected to fullclinical evaluation, EMG & NC studies, evoked potentials, CSF examination & MRIbrain & Spinal cord. The results showed that CNS involvement was found in 25% ofCIDP patients. Those with CNS involvement had more frequently evidence ofclinical CNS affection & abnormal evoked potentials.