Abstract Aims Inflammation is thought to play a role in heart failure (HF) pathophysiology. Neutrophil‐to‐lymphocyte ratio (NLR) is a simple, routinely available measure of inflammation. Its relationship with other inflammatory biomarkers and its association with clinical outcomes in addition to other risk markers have not been comprehensively evaluated in HF patients. Methods We evaluated patients with worsening or new‐onset HF from the BIOlogy Study to Tailored Treatment in Chronic Heart Failure (BIOSTAT‐CHF) study who had available NLR at baseline. The primary outcome was time to all‐cause mortality or HF hospitalization. Outcomes were validated in a separate HF population. Results 1622 patients were evaluated (including 523 ventricular ejection fraction [LVEF]