Greece is among the countries with the highest smoking prevalence (43.8% for ages 15+), ranking third globally and second among EU countries. The high proportion of smoking population makes smoking the leading risk factor for death and disability. This habit has a detrimental impact on health, creating a cost to society. Our aim is to measure the economic cost of diseases attributable to smoking and secondhand smoke in Greece. The method used is the Cost of Illness approach. The economic cost consists of direct costs, such as healthcare expenditures, and indirect costs capturing the productivity loss due to morbidity and mortality. Using estimated smoking attributable deaths and disability from the Global Burden of Diseases Study 2016, we find that the total economic cost is € 6.88 billion (3.95% of GDP); 8.9% of total cost is attributable to secondhand smoke; the direct cost of smoking (secondhand smoke) is slightly less (more) than the indirect cost; the indirect cost is higher for males; musculoskeletal disorders and cardiovascular diseases comprise the greatest fraction of morbidity and mortality cost, respectively. Smoking imposes a heavy economic burden in Greece, underlining the need for efficient interventions, including better implementation of existing policies.