OBJECTIVE: Nursing home-acquired pneumonia characteristically affects elderly patients with multiple comorbidities; it is associated with multidrug-resistant (MDR) pathogens and a high mortality. We studied the specific impact of age on the presentation, etiology and outcome of patients with NHAP. METHODS: Data from the prospective multicenter CAPNETZ database were used for a comparison of the hospitalized younger nursing home residents with pneumonia to those aged >/= 65 years as regards clinical presentation, comorbidity, severity at presentation, etiology, and outcome. RESULTS: Amongst 618 patients with NHAP, 16% of patients (n = 100) were aged; 65 years. Comorbidity was present in most patients with NHAP but the pattern of comorbidity differed significantly. The rate of potential MDR pathogens was low among both age groups (together around 5%). According to the CRB-65 score, NHAP presentation was less severe in the younger patients. Short- and long-term mortality was twice as low in the younger patients with rates of 12.9% vs 26.6%, and 24.3% vs 43.8%, p = 0.014 and 0.002), respectively. In contrast, the usage of mechanical ventilation was more than two-fold higher (12% vs 5%) (p = 0.008) in younger patients. Antimicrobial treatment strategies did not account for different outcomes. CONCLUSIONS: A considerable proportion of patients with NHAP are: 65 years of age. They differ from older patients in terms of clinical presentation, frequency and type of comorbidity, as well as outcome. NHAP is a heterogeneous entity, with age and comorbidity as the main determinant of NHAP characteristics.