Mandu is commonly meat-filled, but because of the seasonal availability of the ingredients and more new items became available in Korea, the dumpling changed over time and resulted in many variations. A variety of names of mandu now exists based on how it was prepared and what ingredients were used.

As mentioned above, there are lots of means on how to cook mandu; specifically, it can be fried, boiled, or steamed. If the dumplings are fried or grilled, they are called gunmandu, when boiled, mulmandu, and when heated, jjinmandu. Boiled and steamed mandu are often mistaken to have similar features, but they differ in the texture of the dough after it has been cooked. A boiled dumpling has the thicker dough, whereas the steamed is softer and lighter. And as for the fried dumplings, it has a soft top, crispy bottom, and tender filling.

These Korean dumplings are traditionally filled with minced pork, green onions, and sometimes kimchi. Nowadays, it can be made with seafood, tofu, chicken, mushrooms, or any other veggie depending on the public's taste. One of the most common ones in Korea is the wang mandu, which is filled with pork and vegetables, much like the Chinese baozi. It is also called "King Mandu" because of its huge size. Also, it is made with fluffy dough rather than thin wheat dough, which makes it different from the other varieties.

Mandus that are mainly eaten in summer are: Pyeonsu - a rectangular-shaped dumpling stuffed with vegetables or sometimes with zucchini, bean sprouts, and beef; Gullin-mandu or gulmandu - a ball-shaped mandu without a covering; Seongnyu-mandu - literally translates to "pomegranate dumpling" because of its shape; Gyuasang - contains minced beef and shredded cucumber, and is shaped like a sea cucumber.

Mandu variations that were originally eaten in the Korean royal court are: Eomandu - a dumpling wrapped with a sliced fish fillet, and Saengchi-mandu - consists of beef, poultry meat, and tofu, and is eaten in Seoul during winter. Other versions of mandu include somandu, which is filled with only vegetables and was consumed initially in Buddhist temple, and Kimchi-mandu that comprises kimchi, making it spicier than the other mandus.

All of these dumplings, regardless of what the filling and how they were cooked, are accompanied by a warm dipping sauce.