['The specific objectives were: 1) to compare the characteristics and 6-month outcomes of community-dwelling seniors in Quebec, Canada, who visited three different emergency department (ED) types and 2) to explore whether the differences in outcomes by ED type were seen among subgroups of seniors.', 'The three types of ED were most specialized, less community-oriented (n = 12); moderately specialized, less community-oriented (n = 28); and least specialized, more community-oriented (n = 28). Administrative databases were used to create a cohort of 223,120 seniors who visited these 68 EDs during a 14-month period. Using a multilevel approach, the following patient characteristics were compared across ED types: sociodemographic (age, sex, urban vs. rural residence, proximity to ED); medical diagnoses and comorbidity burden; and utilization of hospital and physician services during the 16 months before the index ED visit. Cox regression analysis was used to model the relationships between ED type and two 6-month outcomes, adjusting for patient characteristics: 1) serious outcomes (death, acute or long term-care admission) among all individuals who made an index visit and 2) outpatient ED visits (without hospital admission) among those discharged either from the ED or hospital. Interactions between ED type and patient age, sex, urban-rural residence, and comorbidity burden were explored.', 'Compared to patients treated at the least specialized EDs, those at the most specialized EDs were more often urban-dwelling, resided outside the health service area of the ED, and had the highest disease burden and prior specialist utilization. Those treated at the moderately specialized EDs were intermediate between these two groups. During the 6 months after the ED visit, the rate of serious outcomes was higher and the rate of outpatient ED visits was lower for the most specialized compared to the least specialized EDs, even after adjustment for patient characteristics. The differences in these outcomes by ED type were attenuated among older patients and those with greater comorbidity.'] Do outcomes of community-dwelling seniors vary by type of emergency department?