Markers of systemic inflammation have been shown to be elevated in blood of patients with chronic obstructive pulmonary disease (COPD) when compared with control subjects without COPD. The origin of systemic inflammation in COPD is unclear. COPD is often accompanied by other chronic diseases that are also associated with systemic inflammation, such as chronic heart failure, diabetes, and arteriosclerosis. Physical inactivity and metabolic syndrome are relevant conditions leading to systemic inflammation in the general population. Recent data indicate that physical inactivity and coexisting metabolic syndrome are also independently related to systemic inflammation in patients with COPD. Concerning asthma, only limited data about systemic inflammatory markers exist. Some studies found systemic inflammatory markers to be elevated in patients with nonallergic asthma and obese patients with asthma. Further research should elucidate the complex relationship between obstructive lung disease, coexisting conditions, systemic inflammation accompanying these different conditions, and the causative role of systemic inflammation for comorbidities in COPD and asthma.