Earlier a judge ordered the strict Chassidic girls' school to pay a fine because it refused to allow male pupils. The school only registers girls because according to Jewish Orthodox teaching men and women should lead separate lives.
The appeal court has now ruled that another judge must reconsider the matter and come up with a definitive ruling.
The parents of the boys aged 8 and 11 wanted to register their children at the school because they live in the neighbourhood. Originally hailing from New York they settled in Antwerp a year ago.