Background: Despite current therapeutic strategies (antibiotics, pleural drainage, intrapleural fibrinolytics), some patients with parapneumonic pleural effusions (PPE) might need surgery. Serum biomarkers, such as, Procalcitonin (PCT) have been associated with clinical scenarios that might benefit from surgery i.e. severe pancreatitis. Aims and Objectives: We sought to determine the clinical utility of serum PCT as a surrogate of surgery in patients with PPE. Methods: This is a prospective observational preliminary report composed of 33 consecutive patients with confirmed PPE. Baseline serum levels of PCT and C-reactive protein (CRP) along with conventional pleural effusion analysis were included. Primary outcome was to analyze if serum PCT could discriminate patients with PPE who required surgery. Results: A total of 33 patients were included for the preliminary analysis. Median (IQR) baseline serum levels of PCT and CRP were 1.25 ng/ml (IQR 0.77-2.8) and 156 mg/dl (IQR 136-247) respectively. 19 (57.5%) patients underwent surgery. Serum PCT was significantly different among groups (surgery 2ng/ml vs non-surgery 0.87ng/ml, p=0.036), while CRP did not reach statistical significance (166mg/dl vs 146mg/dl, p=0.081). Logistic regression analysis showed that serum PCT have a trend toward to predict surgery (OR 1.57, CI 95% 0.97-2.63, p=0.072). Conclusions: Among patients with PPE, baseline serum PCT was higher in the group of patients who required surgery. Subsequent inclusion of patients could reinforce the association with surgery.