Kielbasa is literally the Polish word for sausage, although native Poles consider it to be a generic term, much like asking for a non-specific soda in a restaurant. There are dozens of varieties of kielbasa available, so shoppers would need to know the specific name of the sausage they desire. In the United States, however, the term "smoked Polish sausage" has almost become synonymous with kielbasa when describing a precooked smoked sausage made with pork, garlic, marjoram, salt and pepper.

Many varieties of sausage sold in grocery stores are of the uncooked German variety, but a true kielbasa is sold precooked in a large hog casing. It is the smoking process that separates Polish kielbasa from other pork sausages. Kielbasa is also seasoned with spices such as garlic and marjoram, not the sage or Italian spices often found in uncooked sausages.

Kielbasa is traditionally served with hearty vegetables such as onions, cabbage and red potatoes. Kielbasa can also be used in conjunction with, or in place of, the smoked andouille sausage often featured in Cajun cooking. Gumbo recipes may call for cooked smoked sausage, and kielbasa makes a good addition to the traditional Cajun side dish of red beans and rice.

There are other dishes in which kielbasa may be an acceptable addition or substitute. Some cooks use kielbasa in place of meatballs or ground beef in spaghetti sauce, for instance. Boiled or grilled kielbasa can be cut into bun-sized portions and served on hot dog buns like bratwurst or Italian sausages. Sliced kielbasa can be combined with sauerkraut in a large pot and heated through on a stove top. Because kielbasa is precooked, it can be boiled, pan-fried, broiled or grilled without concern about raw or undercooked pork.

The product sold as Polish sausage or kielbasa in many grocery stores is not necessarily the authentic variety created in Poland and other eastern European countries. Sometimes cheaper cuts of pork, beef and chicken are combined with sodium nitrites and liquid smoke to create a more commercially viable form of kielbasa, but the ingredients of authentic kielbasa are simply the best cuts of pork seasoned with salt, pepper, garlic and possibly marjoram. Kielbasa used to be "cold smoked" for a few days, but it is now "hot smoked" by placing the stuffed sausage casings in a smoker for several hours.