Avulsion of the brachial plexus is considered the most severe injury of the peripheral nerve. The present study provides a description of the response of ChAT within the ventral horn of the rat cervical spinal cord following avulsion of the brachial plexus. The result demonstrates that the intensity of immunoreactivity of ChAT positive neurons and neuropil background increases in the first 3 days following avulsion and then decreases. The number of ChAT-positive motorneurons in the ventral horn in the lesion side is 84.4% compared to the normal side during the first 3 days post-avulsion, at 7 days the number of ventral horn neurons drops to 64.4% and at 21 days post-avulsion it becomes 44.1%. In the sixth week post-avulsion, only 24.8% of the ventral horn neurons still persist.