The French education minister has said that nearly 300 pupils arrived at school on Monday wearing the abaya, the long Muslim robe which was banned in schools last week, reports BBC News.
Most of the girls agreed to change into other clothes.
According to official figures, 298 girls - mainly aged 15 or more - turned up at school in the banned garment.
Under instructions laid down by the ministry, there followed in each case a period of dialogue with school staff.
Most girls then agreed to dress differently and were able to start classes.
However, 67 girls refused to comply and were sent home.
A further period of dialogue with their families will now ensue. If that fails, they will be excluded.
Set against the 12 million school boys and girls who started term on Monday, the government believes the figures show that its ban has been broadly accepted.
However, a legal challenge by a group representing some Muslims goes before the courts later today.
At the end of August, the education minister announced that pupils would be banned from wearing the loose-fitting full-length robes worn by some Muslim women in France's state-run schools at the start of the new school year on 4 September.