Kiloh-Nevin syndrome was first described in 1948 by Parsonage and Turner and further defined in 1952 by Kiloh and Nevin. The aetiology is highly debated. Two common causes of Kiloh-Nevin syndrome are compression neuropathy and brachial plexus neuritis. In this study the results in six patients who were treated operatively and were evaluated after a mean follow-up of 42 months (range: 24 to 60), are presented. Retrospectively, two subgroups could be identified based on initial clinical presentation and EMG: one subgroup of patients presented with a compression neuropathy and the other subgroup presented with brachial plexus neuritis. An important difference in outcome was seen between the two subgroups. There were excellent results after surgical decompression in the patients with a compression neuropathy, whereas the results after surgical decompression in the subgroup presenting with brachial plexus neuritis were less predictable. The data presented here and the data found in the literature, suggest that if the clinical image and the EMG suggest a compression neuropathy, surgical decompression, after two months of conservative treatment, will give excellent results. If the clinical image and EMG suggest brachial plexus neuritis, a conservative treatment may be more appropriate.