Background:　Mean　platelet　volume　(MPV),　reflecting　the　platelet　production　rate　and　stimulation,　is　an　inflammatory　marker　for　cardiovascular　disease,　inflammatory　bowel　disease,　and　rheumatoid　arthritis.　However,　the　associations　between　MPV　and　chronic　obstructive　pulmonary　disease　(COPD)　are　not　in　agreement.　Methods:　Ninety　participants　with　an　exacerbation　of　COPD　were　investigated,　and　were　reassessed　when　convalescent.　Ninety　controls　were　matched　for　age,　gender,　body　mass　index,　smoking　index,　and　medication　use.　Blood　samples　were　collected　for　measurements　of　MPV　and　other　laboratory　data,　and　pulmonary　function　was　also　assessed.　Results:　MPV　is　significantly　increased　in　convalescent　COPD　patients　compared　with　healthy　controls,　and　further　increased　in　COPD　patients　with　an　acute　exacerbation.　MPV　was　positively　correlated　with　high-sensitivity　C-reactive　protein　both　in　the　exacerbation　and　convalescence　periods　of　COPD,　and　negatively　correlated　with　FEV1　%　predicted　and　FEV1/FVC　in　the　convalescent　COPD　patients.　Conclusions:　MPV　may　be　regarded　as　a　quick　and　reliable　tool　in　the　assessment　of　inflammatory　response　in　the　progression　of　COPD.　(C)　2015　Elsevier　B.V.　All　rights　reserved.