The scheme, which has been a major success in the city's three-year-old education action zone, takes teachers out of the classroom and gives them coaching.
The Office for Standards in Education said it had helped raise teaching grades at inspection. And, in one of the most positive reports yet on an action zone, it praised the zone for "beginning to make a significant contribution" to raising standards in primary schools.
The programme is modelled on schemes for managers in industry. Teachers are observed by mentors in class before being released to discuss their performance with a "coach", while another member of the mentoring team covers.
With the help of the mentor, the teacher works out a personal development plan. He or she then returns to lessons with the mentor observing and assisting. So far, 240 teachers - around two-thirds of those in the zone's 14 schools - have benefited, getting between 12 and 50 hours' coaching a term. The scheme costs the zone pound;250,000 a yea.
Zone chief executive Rosie Connor said that heads had been so impressed that they were looking to run "in-house" mentoring from September. The programme was also helping schools to recruit and retain teachers in an unpopular area.
She added: "It's been tremendously popular with teachers. The chance of a period of reflection away from the hustle and bustle of the classroom is welcomed by many, and traditional training courses often lack the personalised approach we offer here.
The zone's key stage 2 test results have soared in the past three years, with the proportion hitting the target level in maths surging by 17 percentage points.
Inspectors said evidence of secondary improvement was less "clear-cut" with the proportion of students gaining five good GCSEs, only one percentage point up between 1998 and 2000, but the zone put this down to a major schools re-organisation in 1999.
The zone, which is supported by most of Leicester's large employers, has raised more than pound;1.8m in sponsorship and is now trying to raise another pound;1m so that it can become self-funding once Government support ends in 2003.