Background: One of the core features of schizophrenia is impaired cognition. However, the severity and pattern of cognitive deficits in antipsychotic-naïve patients with first-episode schizophrenia still remains a little unclear, because previous studies have often employed relatively small and heterogeneous samples. The goal of this study is to identify the profile and severity of cognitive deficits in antipsychotic-naïve, first-episode patients with schizophrenia across a range of cognitive domains. Methods: Forty-eight antipsychotic-naïve patients with first-episode schizophrenia and 48 matched healthy controls were administered a comprehensive battery of neuropsychological tests to assess domains of cognitive deficits in schizophrenia. Cognitive domains were assessed using composite scores, calculated by grouping selected tests, based on which cognitive domain they theoretically were deemed to putatively assess. Results: There were significant deficits in intelligence and on almost all cognitive domains, including speed of processing, sustained attention, working memory, executive functions, verbal learning and memory, visual learning and memory, reaction time, and speed of executive processing. Only emotion recognition was not significantly impaired. Discussion: At the first stage of illness, antipsychotic-naïve patients with schizophrenia display moderate/severe impairments in the majority of cognitive domains assessed. The results support the contention of global cognitive impairments in schizophrenia.