Now, girls at John Colet School in Wendover, Buckinghamshire, have to wear trousers from January 2012.
The school's head, Christine McLintock admitted that some parents had been angered by the change of uniform code, but added that most of the female pupils wear trousers rather than skirts anyway.
"Some parents have been upset by the decision, but a number have thanked us for taking a firm line."
Mrs McLintock had written to parents to inform them of the skirt ban, saying that some girls were wearing garments which '"ailed to cover the wearer's modesty, particularly when walking up stairs".
She also said that girls going to and from school in very short and tight skirts gave the school a poor image within the local community.
"The way that our students look is the public face of the school and reflects on the whole school community," she said.
The school said it would provide two pairs of 'appropriate' trousers for any girls whose families would face financial hardship because of the rule change.
An Ipswich school implemented a similar skirt ban back in August.
How would you feel if your daughter was banned from wearing skirts?
Do you think the head is right to have made this decision?