Neglect and hemianopia represent frequent disorders in brain damaged patients. Differential diagnosis of both disorders may be difficult since both may present in diagnostic tests and daily life as a failure to perceive or react to stimuli in the contralesional hemispace or hemifield. The present paper summarizes several useful techniques in order to achieve a correct distinction. After a short review of the clinical phenomenology of hemianopia and -neglect the following topics are described: (1) subjective complaints and awareness of deficits (2) aetiology and lesion localisation, (3) uni-versus multimodal deficits; (4) extinction, (5) drawing from memory; (6) visual-spatial disorders; (7) line bisection, (8) effectiveness of attentional "cueing" strategies; (9) specific perimetric techniques; (10) visual evoked potentials and eye movement registration. The differences between hemianopia and -neglect are contrasted for all these topics. Taken all these possible features together the association and/or dissociation of hemineglect and postchiasmatic scotomata can efficiently be diagnosed. The results are summarized in a table at the end of the paper.