Sepsis is an especially common affliction in the elderly and despite its increased prevalence and mortality in older people, the immune response of the elderly during septic shock appears similar to that of younger patients. In the original study we conducted a global gene expression analysis of circulating neutrophils from elderly and young septic patients, as well as from age-matched healthy controls, to better understand how elder individuals respond to severe infectious insult (Pellegrina et al., 2015). Here we provide additional details pertaining processing and statistical analysis of the microarray data. Raw and normalized datasets linked to this project have been deposited in the Gene Expression Omnibus (GEO) database under accession number GSE67652.