BACKGROUND: Visual-spatial neglect (VSN) is a neuropsychological syndrome, and right-hemisphere stroke is the most common cause. The pathogenetic mechanism of VSN remains unclear. This study aimed to investigate the behavioral and event-related potential (ERP) changes in patients with or without VSN after right-hemisphere stroke. METHODS: Eleven patients with VSN with right-hemisphere stroke (VSN group) and 11 patients with non-VSN with right-hemisphere stroke (non-VSN group) were recruited along with one control group of 11 age- and gender-matched healthy participants. The visual-spatial function was evaluated using behavioral tests, and ERP examinations were performed. RESULTS: The response times in the VSN and non-VSN groups were both prolonged compared with those of normal controls (P?<?0.001). In response to either valid or invalid cues in the left side, the accuracy in the VSN group was lower than that in the non-VSN group (P?<?0.001), and the accuracy in the non-VSN group was lower than that in controls (P?<?0.05). The P1 latency in the VSN group was significantly longer than that in the control group (F[2, 30]?=?5.494, P?=?0.009), and the N1 amplitude in the VSN group was significantly lower than that in the control group (F[2, 30]?=?4.343, P?=?0.022). When responding to right targets, the left-hemisphere P300 amplitude in the VSN group was significantly lower than that in the control group (F[2, 30]?=?4.255, P?=?0.025). With either left or right stimuli, the bilateral-hemisphere P300 latencies in the VSN and non-VSN groups were both significantly prolonged (all P?<?0.05), while the P300 latency did not differ significantly between the VSN and non-VSN groups (all P?>?0.05). CONCLUSIONS: Visual-spatial attention function is impaired after right-hemisphere stroke, and clinicians should be aware of the subclinical VSN. Our findings provide neuroelectrophysiological evidence for the lateralization of VSN.