This study reports the Standardised Mortality Ratio (SMR) by age and sex among public mental health patients in Singapore. The authors also examine the differences between those who were classified as "inpatient deaths" and those who were classified as "outpatient deaths". Mortality was 5.1 times that of the general population and the SMR was most accentuated in the younger, female patients. Of the 217 deaths documented over two years, schizophrenia was the most common diagnosis. Inpatient deaths (N = 120) occurred in older patients with prior physical illness who died of natural causes. In contrast, outpatient deaths (N = 97) involved younger patients with no previous illness and the majority jumped to their deaths. Mortality studies are necessary in monitoring the efficacy of mental health provisions.