BACKGROUND: Older adults experience a higher risk of death in the emergency departments (EDs), in part, as a result of their comorbidities. A treatment-limiting decision is often reported for older adults who die in the EDs. The Charlson Comorbidity Index (CCI) is a validated method for the scoring of comorbidities. Whether an association between the CCI and treatment-limiting decisions exists remains unknown. OBJECTIVE: To determine whether the CCI was associated with the treatment-limiting decisions made for older patients who die in the EDs. METHODS: A total of 2,095 patients >/=65 years old who died in the EDs in France and Belgium were prospectively included between 2004 and 2005. The recorded data included: 1) the CCI score; 2) patient age; 3) gender; 4) living in senior housing facilities; 5) hospitalizations occurring in the previous year; 6) presence of functional limitations (according to the Knaus classification); 7) chronic diseases; and 8) presence of organ failure(s). A treatment-limiting decision was defined as a predetermined choice not to implement therapies that would otherwise be required to sustain life. RESULTS: A treatment-limiting decision was identified in 993 (47%) patients. Fully-adjusted logistic regression model showed that a CCI >/= 5 (OR=25.56 with P=0.037), age >/=85years (OR=20.33 with P<0.001), living in an institution (OR=0.15 with P=0.017), hematologic (OR=6.92 with P=0.020) and respiratory disease (OR=0.17 with P=0.046), and neurologic causes (OR=0.20 with P=0.010) of organ failure were significantly associated with treatment-limiting decisions. CONCLUSION: An elevated CCI score (>/=5) was associated with a treatment-limiting decision in elderly patients evaluated in the EDs. Further research is needed to corroborate this finding.