An Italian beef sandwich consists of thin slices of beef served inside Italian bread or some other crusty bread (often soaked), which has been cut lengthwise and into individual portions. (The "Italian Bread" commonly used in Chicago is a white loaf with a high gluten content and little to no sourdough flavor, made to be reminiscent of what many think of as being Italian restaurant bread). Even though it is served on Italian bread sliced lengthwise, this is the only thing it has in common with submarine sandwiches. Italian beef is made using cuts of beef from the sirloin butt (Scala's) or the top/bottom round wet-roasted in broth with garlic, oregano and spices until medium rare or medium. The roast is then cooled, then sliced very thinly ("shaved") using a deli slicer, and then served dripping wet after a reintroduction to its reheated beef cooking broth, topped off with sauteed green bell peppers, or hot Chicago-style "Giardiniera" peppers (mix of Serrano peppers, carrot, cauliflower, celery, olives, and oil/spices), or rarely marinara sauce by request; hence the need to use a chewy bread for this dish: a softer bread would disintegrate.

The sandwich was featured on the PBS special Sandwiches That You Will Like. The Italian beef sandwich is a dish associated with Chicago. It is difficult to obtain outside the Chicago area. Italian Beef sandwiches can be found at most hot dog stands and small Italian-American restaurants throughout the city and its suburbs. Most Chicago hotdog-stand-style Italian Beef retailers purchase pre-seasoned, pre-cooked, and pre-sliced Italian Beef with separate cooking broth ("au jus"), and then heat and serve, while other retailers purchase the raw beef cuts and prepare it themselves.