Objective To analyze the prognosis of elderly patients with community-acquired pneumonia (CAP) and its correlation with serum angiopoietin 2 (Ang-2), activated protein C (APC) and pentraxin 3 (PTX3) levels. Methods A total of 508 elderly patients with CAP in the hospital from March 2021 to March 2024 were divided into death group (n=104) and survival group (n=404) according to the survival status at 28 days after admission. Another 110 healthy subjects with physical examination were included in the control group. The levels of serum Ang-2, APC and PTX3 were compared, and their correlation with prognosis was explored by Pearson correlation analysis. Results In this study, 404 cases survived after 28 days and 104 cases died. The levels of C-reactive protein, procalcitonin and interleukin-8 and the proportion of severe condition in the survival group were lower than those in the death group (P<0.05). The level of serum APC in the case group and the death group was lower than that in the control group and the survival group (P<0.05), while the levels of Ang-2 and PTX3 were higher than those in the control group and the survival group (P<0.05), respectively. Serum APC level was negatively correlated with community-acquired pneumonia in the elderly CAP (r=-0.476, P<0.05), while Ang-2 and PTX3 were positively correlated with prognosis (r=0.489, 0.502, P<0.05). Conclusion Serum levels of Ang-2 and APC in elderly patients with CAP are decreased and the level of PTX3 is increased. Serum Ang-2 and APC levels are negatively correlated with elderly CAP, and PTX3 is positively correlated with prognosis.