A major component in Philadelphia's early economy, trade remains important to the state.

According to federal data, sales from wholesale trade in 1997 totaled $167 billion, 8th highest in the US. The main items sold were groceries and related products; machinery, equipment, and supplies; motor vehicles and automotive parts and supplies; metals and minerals (excluding petroleum); electrical goods; and petroleum and petroleum products.

Pennsylvania ranked 5th in the US in sales from retail trade in 1997, with almost $113 billion. The top categories in terms of numbers of businesses were automotive dealers, 12%; food stores, 11%; and restaurants or taverns, 30%. Philadelphian John Wanamaker opened the world's first department store in 1876; by 1997, Pennsylvania had over 1,600 shopping centers, about one-third of them in the Philadelphia and Pittsburgh metropolitan areas.

During the colonial era, Philadelphia was one of the busiest Atlantic ports and the leading port for the lucrative Caribbean trade. Philadelphia remains one of the country's leading foreign trade centers; the main import suppliers are the United Kingdom, Indonesia, Saudi Arabia, Venezuela, and Algeria. In 1998, total exports of Pennsylvania goods had a value of $16 billion (10th in the US).