Susan Allen, 39, from Liverpool was charged with conspiracy to supply cocaine in October 2005.
She was granted bail at Liverpool City Magistrates' Court, but this was contested by the Crown Prosecution Service (CPS).
Four days later an appeal hearing took place at Liverpool Crown Court where Judge Henry Globe denied Allen the chance to appear.
According to the European Court of Human Rights decision, he said: "What do you want me to do if I were to ask her to come up into the dock, just look at her? Does that add anything to anything that you are suggesting?
"I have a very clear picture of the sort of person who is going to walk into the dock. No doubt she is going to be very worried. It must be a very intimidating experience for anybody of no previous convictions who has recently been taken into custody, to be brought into a court as large as this.
"I can imagine full well what is going to happen when she walks in. But given the fact that I can imagine that, and I have seen it happen many times, what else am I going to notice?"
Allen claimed she should have been allowed to attend the hearing because she potentially faced a long period in prison before her trial for drug dealing.
Under domestic law, a defendant is not allowed to attend appeal hearings about their bail unless there are "exceptional circumstances".
But on Tuesday a panel of seven judges in Strasbourg found "fairness required that the applicant's request to be present at the appeal be granted".
It award Allen 1,000 euros (£880) compensation which the Government must now pay.
She was sentenced to four years in prison in 2007 for two counts of conspiracy to supply class A drugs.
A Ministry of Justice spokeswoman said the Government will now consider whether to change court rules which set out when defendants have the right to appear.
She said: "We are considering the judgment. It is for the Criminal Procedure Rule committee to consider if changes to the rules are necessary."