Deficiency of enzyme acid beta-galactosidase causes GM1 gangliosidosis. Patients with adult GM1 gangliosidosis typically present with generalized dystonia. We describe clinical, bone marrow, and radiological features of adult GM1 gangliosidosis to help improve its recognition. We report 3 Indian patients and review of reports between 1981 and October 2002. The disease frequently is reported in the Japanese literature (75%). Patients are normal at birth and have normal early motor and mental development. Onset is within the first decade with abnormal gait, or worsening of speech is an initial symptom. Dystonia occurs in 97% of patients. Facial dystonia described as "facial grimacing" observed in approximately 90% could be an important clinical clue. Dysarthria/anarthria (97%) is frequent, and eye movements are normal. Bone marrow examination may show Gaucher-like foam cells (39%). Magnetic resonance imaging (MRI) frequently (90.9%) shows bilateral symmetrical putamenal hyperintensities on T2-weighted and proton density images. Diagnosis is confirmed by demonstrating deficiency of beta-galactosidase. Adult (Type 3) GM1 Gangliosidosis commonly presents with generalized dystonia with prominent facial dystonia, severe speech disturbances, and normal eye movements. Bone marrow frequently shows Gaucher-like foam cells. MRI shows typical lesions in the putamen. Deficiency of beta-galactosidase in fibroblasts confirms the diagnosis.