According to El Escorial criteria, amyotrophic lateral sclerosis (ALS), combined with other neurologic disorders, such as dementia and parkinsonism, is defined as ALS-plus. These overlaping syndromes are extremely rare. Here we report 5 cases (3 men, 2 women) of ALS-plus; mean age at the onset of symptoms was 67 years (range, 65-72). In 3 patients, motoneuronal signs preceded the onset of parkinsonian syndrome. In 4 cases, the clinical picture was characterized by the prevalence of motoneuronal signs. Parkinsonism was poorly responsive to L-dopa treatment in all patients. The clinical course did not differ from that expected in patients with only ALS. Our clinical observations and neuropathological reports of nigral neuronal loss in ALS patients suggest a common pathogenic mechanism underlying these disorders.