To detect and analyze errors, health care has traditionally relied on retrospective methods such as incident reporting and root cause analysis. This commentary draws a contrast between this approach and that used in the nuclear power industry, which focuses on prospective error detection through the use of a robust peer-to-peer assessment process. Nuclear power facilities can request peer review by an independent non-regulatory body, which conducts a detailed safety assessment and makes specific recommendations for safety improvement. The authors recommend developing a similar process for hospitals and discuss barriers that would need to be overcome in order to implement such a process.