This study determines the socio-demographic and clinical correlates of suicide attempts in Chinese schizophrenia outpatients and their impact on patients' quality of life (QOL). Two hundred and fifty-five clinically stable schizophrenia outpatients were randomly selected in Hong Kong (HK) and their counterparts matched according to sex, age, age at onset and length of illness were recruited in Beijing (BJ). All subjects at both sites were interviewed by the same investigator using standardized assessment instruments. Basic socio-demographic and clinical data and history of suicide attempts were collected. The lifetime prevalence of suicide attempts was 26.7% in the whole sample and 20% and 33.6% in the HK and BJ samples, respectively. Patients with a history of suicide attempts were less likely to receive depot antipsychotic (AP) medication, more likely to receive clozapine, benzodiazepines (BZD) and higher doses of APs; were younger at onset, had more hospitalizations; had more severe positive, depressive, anxiety and extrapyramidal (EPS) symptoms; were poorer QOL in the physical, psychological, social and environmental domains; and were more likely to be BJ residents. In multiple logistic regression analysis, early age at onset, poor physical QOL, use of clozapine and BZDs, and study site (HK vs BJ) were significant contributors to lifetime suicide attempts. Significant difference was found between matched samples in HK and BJ with respect to suicide attempts. HK is a cosmopolitan city with a Western social structure and mental health system, whereas in BJ more traditional Chinese cultural values predominate, with a mental health policy radically different from that of HK. These differences suggest that socio-cultural factors play a significant role in determining suicide attempts in schizophrenia.