Background: Acute pulmonary embolism is a serious medical condition that has a substantial global impact. Inflammation plays a role in the pathophysiology and prognosis of acute pulmonary embolism (APE). The aim of the present study was to investigate the prognostic value of admission parameters for complete blood count (CBC) in APE. Methods: A total of 203 patients who were hospitalized with diagnosed APE were retrospectively enrolled in the study. Clinical data, PESI scores, admission CBC parameters, neutrophil-to-lymphocyte ratio (NLR) and plateletto- lymphocyte ratio (PLR) were all recorded. The clinical outcomes of study subjects were determined by the reported patient 30-day mortality and long-term mortality. Results: During a median follow-up period of 20 months [interquantile range 17], 34 subjects in the study population (17%) died. NLR and PLR levels were significantly higher in patients who died within the 30 days (n = 14) [9.9 (5.5) vs. 4.5 (4.1), p = 0.01 and 280 (74) vs. 135 (75), p = 0.01, respectively] and during the long-term follow-up (n = 20) [8.4 (2.9) vs. 4.1 (3.8), p = 0.01 and 153 (117) vs. 133 (73), p = 0.03, respectively] when compared to the patients that survived. In Cox regression analysis, age, systolic blood pressure, systolic pulmonary arterial pressure, PESI scores (HR 1.02 95%CI 1.01-1.04, p = 0.01), elevated levels of NLR (HR 1.13 95%CI 1.04-1.23, p = 0.01) and PLR (HR 1.002 95%CI 1.001-1.004, p = 0.01) were independently correlated with total mortality. Conclusions: Admission NLR and PLR may have prognostic value in patients with APE.