The ICJ was asked to rule on the legal consequences of the fence after the United Nations (news - web sites) General Assembly voted overwhelmingly in early December for a so-called advisory opinion from the court.
Its findings will be non-binding, but a negative outcome would be a great embarrassment for Israel.
The barrier, which Jerusalem calls a "terror prevention fence", stretches over hundreds of kilometres (miles) and is built mostly of wire fencing, but there are also sections made of eight-metre-high (25-feet-high) cement slabs.
The Israeli government of Prime Minister Ariel Sharon (news - web sites) insists the barrier is vital for the security of the nation because it will help to prevent Palestinian suicide attacks.
The Palestinians argue that the barrier, which cuts deep into the West Bank in some areas and completely cuts off several towns and villages, is a landgrab in order to pre-empt the borders of their promised future state.
Israel has consistently rejected the ICJ's competence in the matter, arguing the court should not rule on what it regards as a purely political issue and asserting their fundamental right to self-defence.
After filing a 150-page document outlining why Jerusalem believes the court should not adjudicate the matter, Israel announced last week that it was boycotting the hearings.
Israel is arguing that its written application outlines its official position clearly and requires no further presentation.
The absence of an Israeli delegation will not change the court proceedings. The ICJ takes all written and oral applications into account to come to a final advisory opinion.
Established in 1946, the ICJ is the UN's highest judiciary body, set up to deal with conflicts between states. The court can also issue advisory opinions on the legality of certain matters. So far the ICJ has issued 24 such opinions.
The advisory opinions are supposed to be strictly legal issues. Israel and some of its supporters are expected to argue that the case is essentially a politically dispute between two parties and is not something to be dealt with in an advisory opinion.
Experts on international law questioned by AFP said it is highly unlikely that the court will decide it is incompetent in the matter.
"The central question is whether or not it is a legal question which has been brought before the court. That is the only criterium, and I think in this case the court will not declare itself incompetent," Phon van den Biesen, a Dutch lawyer who has worked on several cases before the ICJ, said.
The court has been asked to give an opinion on the legal consequences of the wall Israel "is constructing on occupied Palestinian territory".
"The argument that it is a political question is not a good one. Every international dispute, every question has both legal and political aspects," Olivier Ribbelink, of the TMC Asser Institute for legal studies in The Hague (news - web sites), told AFP.
According to the court, another 43 states besides Israel have lodged written statements with the ICJ including Russia, the United States and several European Union (news - web sites) (EU) members.
The UN General Assembly and many Arab and European countries have condemned the construction of the barrier, which is dubbed by Palestinians as an "Apartheid Wall".
Both the United States and the European Union, however, have warned that the ICJ hearing would serve to further undermine the peace process.
The Palestinian Authority (news - web sites), the League of Arab States and the Organisation of the Islamic Conference have also filed written statements but none of the documents has been released to the public.
On Monday, February 23, the court will start with hearings at which states and interested parties may give oral presentations. It is not yet known how many parties have applied to speak.
The proceedings are expected to last at least a week. No date has been set for a ruling.
