A forty-six year old man with chronic renal failure and a toxic chronic liver disease developed progressive muscle weakness after a long trial with colchicine. Physical exam revealed muscle weakness and proximal muscle atrophy with hyporeflexia. Serum levels of creatine kinase were high and signs of myopathy and axonal and demyelinating polyneuropathy was evidenced in electrophysiological studies. Muscle biopsy disclosed a vacuolar myopathy, disruption of myofibers and dilatation of sarcoplasmic reticulum. The clinical pictures was attributed to a toxic myopathy and polyneuropathy due to colchicine, thus this treatment was discontinued. Four week later, the patient was symptom free, the levels of seric creatine kinase were normal and a new muscle biopsy was normal, with disappearance of previous histological findings.