The latest crop of head teachers in England are more confident and have a better understanding of leadership and management, according to Ofsted.
The inspectorate says the government's Headlamp training programme - introduced in 1995 - has been "good" or "very good" in most cases.
But there were also "several significant areas of weakness".
This include failure of most training providers to tailor the courses to the needs of individual head teachers.
Ofsted says little was done to address these issues, even though it had raised them in earlier reports.
New scheme
Headlamp is being replaced from this term by a new head teacher induction programme.
This is run by the National College for School Leadership, which acted after its own review of how Headlamp was working.
Ofsted says it is important the lessons identified in its report are applied to the new scheme.
The Department for Education and Skills said the college had done that.
"Each year 1,500 to 1,800 new heads take up their first headship post and we look forward to the success of this new programme, which is based on the heads' individual needs assessment."