Background: Chronic obstructive pulmonary disease (COPD) is associated with high-grade systemic inflammation such as elevated blood leukocyte counts, acute phase proteins, and inflammatory cytokines. Involvement of activated platelets and their indices in the pathophysiology of COPD is not surprising due to its central role in hemostasis and thrombosis. Objective: to study platelet indices in patients with acute exacerbation of COPD (AECOPD). Methodology: 100 patients with AECOPD and 100 patients with stable COPD matched for age and gender were included in this case-control study.  Age, gender, smoking status, and index were recorded.  Spirometric-indices (FVC%, FEV₁%, FEV₁/FVC ratio), arterial blood gases, hepatic, renal functions tests, erythrocyte sedimentation rate (ESR), total leucocyte count (TLC), platelet (PLTs) count, mean platelets volume (MPV), platelet distribution width (PDW), plateletcrit (PCT%), and platelet large cell ratio (P-LCR)  were measured. Results: Compared to the stable COPD group, the AECOPD group had lower MPV, PDW, and P-LCR with higher PCT%. The TLC, PLTs count, and ESR were significantly increased in AECOPD patients. PDW was inversely correlated with FEV₁ and the FEV₁/FVC ratio in the exacerbation group but not in the stable group. PCT% and FEV₁/FVC ratio were positively correlated in AECOPD group while they were inversely correlated in the stable group. The PCT% and smoking index were positively correlated in the AECOPD group. The P-LCR and FEV₁/FVC ratio were inversely related in the AECOPD. Regarding ACOPD severity, the PCT% and P-LCR significantly differed between patients with mild, moderate, and severe exacerbation, while PLTs count, MPV, or PDW did not differ. Conclusion: Platelet-indices, which measure platelet activity, can be considered as a simple, and minimally invasive biomarker for COPD exacerbation. PLTs count and MPV are important indicators of COPD exacerbation.