Unilateral neglect has been produced in monkeys by making discrete lesions in the frontal lobe. In man, neglect usually accompanies lesions of the nondominant parietal lobe. This report concerns six cases of unilateral neglecthemispatial agnosia, inattention, and extinction-following nondominant frontal lesions. Three patients had lesions on the medial surface of frontal lobes; three had lesions on the dorsolateral surface. The anatomic locus of these le sions was determined by pathological examination in one patient and by radioisotope scanning in five. © 1972 American Academy of Neurology.