Robert Tims, the headmaster of St Leonards School in St Andrews, believes the move will help his sixth-formers clinch university places, and boost his roll. "British universities love it because they understand it shows who are the very best candidates," he said.
The IB qualification, which must include arts and science subjects, is offered at three levels, culminating in the diploma for 16 to 19-year-olds.
It is offered by 1,900 schools in 124 countries and taken, at the last count, by 488,000 students who are expected to be "active learners, well-rounded individuals and engaged world citizens".
Only two other schools in Scotland have IB courses, Fettes in Edinburgh and the International School of Aberdeen, which are both private.
St Leonards, which is Mr Tims's first headship, has some 407 students aged five to 18, with around 100 in the sixth form. Nearly half are international students.
Mr Tims opted for the baccalaureate after it was introduced at his previous school, Malvern College in Worcestershire. "It is a sea change in the way the school, and the teachers, look at what we are presenting."
Teachers have received five days' training in the system and, Mr Tims says, they have supported the switch. Pupils pick subjects from six blocks. Some are compulsory (English and maths) and the others offer a choice of social subjects, languages or sciences. The sixth offers a selection of arts courses, or the chance to study a second science or a second language.
In addition, there is room for games, personal study, ICT, or even English as an additional language for foreign students. At the end of two years, pupils sit two or three exams in each subject, over three weeks. This may mean more exams, but Mr Tims believes it will mean less pressure. "We haven't got deadlines of examinations during the year on a small part of the course any more," he said.
Mr Blair announced that the Government would pay to train teachers in 100 schools to offer the IB, with the aim of making it available in at least one school in every education authority in England by 2010.
The only state school in Scotland to have offered the IB in the past was Lockerbie Academy. It was abandoned in 1998 after five years because the affiliation and exam fees became too expensive, Graham Herbert, the head, said.