AKI is frequent in critically ill patients, in whom the leading cause of AKI is sepsis. The role of intrarenal and systemic inflammation appears to be significant in the pathophysiology of septic-AKI. The neutrophils to lymphocytes and platelets (N/LP) ratio is an indirect marker of inflammation. The aim of this study was to evaluate the prognostic ability of N/LP ratio at admission in septic-AKI patients admitted to an intensive care unit (ICU). This is a retrospective analysis of 399 septic-AKI patients admitted to the Division of Intensive Medicine of the Centro Hospitalar Universitário Lisboa Norte between January 2008 and December 2014. The Kidney Disease Improving Global Outcomes (KDIGO) classification was used to define AKI. N/LP ratio was calculated as: (Neutrophil count×100)/(Lymphocyte count×Platelet count). Fifty-two percent of patients were KDIGO stage 3, 25.8% KDIGO stage 2 and 22.3% KDIGO stage 1. A higher N/LP ratio was an independent predictor of increased risk of in-hospital mortality in septic-AKI patients regardless of KDIGO stage (31.59±126.8 vs 13.66±22.64, p=0.028; unadjusted OR 1.01 (95% CI 1.00-1.02), p=0.027; adjusted OR 1.01 (95% CI 1.00-1.02), p=0.015). The AUC for mortality prediction in septic-AKI was of 0.565 (95% CI (0.515-0.615), p=0.034). The N/LP ratio at ICU admission was independently associated with in-hospital mortality in septic-AKI patients.