Double crush syndrome (DCS) was first described by Upton and McComas who proposed that focal compression of an axon often occurs at more than one level. The aim of the study was to support the hypothesis of DCS of the median nerve on the basis of available diagnostic methods. 30 patients (25 F and 5 M aged 33-73, mean 54.6+/-8.2 years) with coexisting carpal tunnel syndrome (CTS) and cervical radiculopathy (CR) were examined. Control group included 40 healthy volunteers (27 F and 13 M aged 17-82, mean 43.1+/-11 years). Medical evaluation comprised clinical examination, X-ray and MR imaging of the cervical spine, electroneurography (ENG) with F-wave and somatosensory evoked potentials (mSEPs) of median nerves. In clinical examination 96.6% of patients suffered from cervical spine pain and nocturnal paresthesies of at least one hand. Muscular atrophy was present in 43.3% in the proximal and in 70% in the distal part of the upper extremity. 30.3% of patients presented with a thoracic scoliosis. On X-ray examination, all patients showed cervical discopathy, mostly C5-C6 (70%) and C6-C7 (53.3%). Using MR investigation, the narrowing of intervertebral foramina was present in 81.25% and narrowing of vertebral canal in 37.5%. On ENG all patients presented with CTS, bilaterally in 73.3%. The F wave was abnormal in 73.3% and mSEPs in 66.7% of patients. Coincidence of MR and mSEPs in view of lateralization was observed in 71.4%. Results supported the DSC hypothesis. DCS evaluation requires both structural and functional diagnosis of peripheral neurones using MRI and electrophysiological examination.