The current study attempts to highlight the stages of Palestine’s joining the World Trade Organization (WTO) and steps that should be followed by Palestine to join the World Trade Organization from the observer to the member. It also clarifies how Palestine joins the World Trade Organization as a state and then as a customs territory. The problem of this study lies in determining the legal effects of Palestine's joining the World Trade Organization as a state on the one hand and as a customs territory on the other. The study aims at clarifying the stages that Palestine will go through in case of joining the World Trade Organization, the steps that Palestine should take to join the World Trade Organization, and the mechanism that should be followed when Palestine joins the World Trade Organization as a state, and then as a customs territory. The study concluded that Palestine must join the World Trade Organization as a customs territory as soon as possible in order to avoid any discussion about the final legal status of its territories according to the Oslo Accords.