Objective Pulmonary embolism (PE) is a serious pathology with high rates of morbidity and mortality. Studies regarding the efficacy of new inflammatory markers as a predictor of mortality in PE have thus far been limited. This study aimed to evaluate the predictive value of platelet/lymphocyte ratio (PLR), neutrophil/lymphocyte ratio (NLR), platelet/mean platelet volume (PLT/MPV), and C-reactive protein (CRP) on short-term and long-term mortality in patients with PE. Material and methods A retrospective, observational cohort study was carried out in a tertiary teaching hospital. Patients with PE hospitalized in the pulmonology ward were enrolled. Their characteristics, hemogram parameters, PLR, NLR, CRP levels, PLT/MPV on admission, and mortality were recorded. The predictive accuracies of inflammatory markers were determined through receiver operating characteristic curves. The risk factors for mortality were further analyzed with Cox regression analysis. Results A total of 828 patients with PE were included in the study. The 1-month mortality was 1%, and the 1-year mortality was 8.5%. An NLR value above 6 was associated with an almost 13-fold increase in short-term (30-day) mortality. We found that an NLR above 3.15 and age were independent risk factors for long-term (1-year) mortality. The other inflammatory markers, namely PLR and CRP, were not found to be associated with long-term mortality. Conclusion PE is a serious condition in the elderly. Elevated NLR values appear to be a good and feasible predictor of inflammation, which can be correlated with higher mortality over both the short-term and long-term periods.