Tet Nguyen Dan (often referred to simply as Tet) is the Lunar New Year, perhaps the most important holiday of the year. The New Year does not fall on the same date every year, although it is always in January or February. The official holiday lasts three days, but it is often celebrated for a full seven days. In many ways, the Tet "holiday season" is not unlike the December "holiday season" in North America. Tet Nguyen Dan literally means "first morning of the first day of the new period." It is believed that the course of these few days determines the events of the coming year. People stop quarreling; children vow to behave; and families make special efforts to gather together. Prior to the celebration, homes are cleaned and painted and decorated with yellow hoa mai (peach blossoms. Many Tet traditions concern Tao Quan, the Spirit of the Hearth or the Kitchen God. It is believed that the Kitchen God leaves the household during Tet to report on the family to the Emperor of Jade. (Cleaning is avoided during Tet, so good luck will not be "swept away.")

New clothes are purchased, and old debts are repaid. Many superstitions and traditions revolve around Tet, the Vietnamese Lunar New Year. One such belief is that when a watermelon is cut open, the redder the flesh, the more luck the family will have in the upcoming year. Families construct a Cay Neu (New Year's tree) from a bamboo pole stripped of its leaves except a few at the top and then decorated with red paper. (Red is believed to ward off evil.) The Cay Neu stands in front of their homes to protect them from evil spirits while Tao Quan is away. Families prepare and partake in feasts that include such rare treats as sup bao ngu (abalone soup) and canh vay ca (shark's fin soup). People carry gifts of food to family and friends.