We aimed to examine whether early life bereavement, as indicator of severe stress, was associated with an increased risk of schizophrenia later in life.Based on population registers, we established a cohort of all children born in Denmark (N = 1 686 416) and Sweden (N = 2 563 659) from 1973 to 1997. Children were categorized as exposed if they lost a first-degree relative during the first 18 years of life. Outcome is the first diagnosis of schizophrenia as either inpatient or outpatient. Log-linear Poisson regression models were used to estimate incidence rate ratios (IRRs).A total of 188,850 children (4.6%) experienced death of a first-degree relative from birth to 18 years of age. Compared with unexposed children, those exposed had overall a 39% higher risk of schizophrenia (= 1.39, 95% CI [confidence interval]: 1.32-1.47). The IRR was particularly high if the family member committed suicide (aIRR = 2.11, 95% CI: 1.90-2.34) or died due to an injury or accident (aIRR = 1.44, 95% CI: 1.27-1.63). The IRR of schizophrenia decreased with increasing child's age at bereavement (P < 0.0001). Children who experienced >1 death during the first 18 years of life (aIRR = 1.79, 95% CI: 1.46-2.19) had a higher risk than those with a single death (aIRR = 1.37, 95% CI: 1.30-1.45).The study suggested that exposure to death of a first-degree relative before 18 years was associated with an increased risk of schizophrenia in later life. The complex mechanisms behind these associations remain to be elucidated.