Historically agricultural, Greece has seen industry replace agriculture as the leading source of income; agriculture accounts for about 5% of the gross domestic product, while industry accounts for some 20%. Tourism, a part of the growing service sector, provides a vital source of revenue. The chief agricultural products are wheat, corn, barley, sugar beets, olives and olive oil, tomatoes, wine, tobacco, and potatoes. Large numbers of sheep and goats are raised.
The country's main industrial centers are Athens, Thessaloníki, Piraiévs, Pátrai, and Iráklion. The principal industries are tourism, agricultural processing, mining, petroleum refining, and the manufacture of textiles, chemicals, and metal products. The chief minerals produced are lignite, petroleum, iron ore, bauxite, lead, zinc, nickel, magnesite, and marble. Electricity is generated mainly by hydroelectric and thermal power stations. Greece has a large merchant fleet, and its chief ports are Piraiévs and Thessaloníki. There is a significant fishing industry in coastal areas.
The main exports are food and beverages, manufactured goods, petroleum products, chemicals, and textiles; the leading imports are machinery, transportation equipment, fuels, and chemicals. The principal trade partners are Germany, Italy, and France.