Schizophrenia impairs both facial emotion processing and sustained attention. Through separate studies, it is known that the presence of a task-irrelevant facial stimulus disproportionately interferes with performance, whereas increasing the salience of task stimulus improves performance during a sustained attention task in patients with schizophrenia. We wished to investigate a potential interaction effect of background facial emotion expression (black and white happy faces vs. grey oval) and target stimulus salience (bright white vs. grey) using the Continuous Performance Test-Identical Pairs version (CPT-IP) in patients with schizophrenia. Thirty-six patients with schizophrenia and 28 healthy control subjects completed 4 different versions of the CPT-IP. We found that healthy controls exhibited higher signal detection sensitivity (d′) when salient target stimuli were presented on the facial background than when the same stimuli were presented on the grey-oval background. By contrast, patients were not affected by background stimuli when target number stimuli were salient. When target number stimuli were not salient, both patients and controls showed higher d′ in the grey-oval background condition compared with the facial background condition. This study highlight the significance of stimulus salience during CPT-IP in schizophrenia as background stimuli did not produce a differential effect on performance. Our results suggest that, in the situations where facial emotion stimuli are present, patients' sustained attention can be deteriorated and that the use of salient materials is important in improving performance in schizophrenia.