Just one in five new teachers found permanent, full-time jobs after qualifying in 2009-10, a survey shows.
The General Teaching Council for Scotland said only 20.5% of new teachers found permanent work, down from the 25.5% recorded for 2008-09.
More probationers have no job at all compared with the previous year, up from 13.5% to 16.2%.
The council's survey analysed the responses of 1222 new teachers, out of the total 2914 probationers who were sent the survey, to establish how unsuccessful they were at finding teaching jobs.
The proportion of those securing only part-time, permanent contracts also fell, to 2.4%. The previous year's rate was 4.5%.
Full-time contracts as supply teachers only were offered to 8.6% of probationers, up from 6.2%, while those who became part-time supply teachers increased from 3.6% to 5.4%.
Anthony Finn, chief executive of the General Teaching Council for Scotland, said the body takes a survey of former probationers every year, reporting its findings to the Scottish Government.
He said: "We note that the number of former probationers not in employment is up from the last time we conducted this survey. This is clearly a cause for concern, as is the drop in the number of former probationers achieving full-time permanent employment.
"We are acutely aware of the financial constraints faced by public bodies across Scotland and accept that this will impact to a certain extent on teacher employment. We must ensure however that these highly skilled new teachers who have been through a teacher induction scheme, described as world class by the Organisation for Economic Co-operation and Development, are able to find work in the classroom, providing a quality education for our children and young people.
"As part of the recent Scottish negotiating committee for teachers agreement, the Scottish Government has agreed with employers to create more jobs for teachers in the coming months. If this aspiration is realised, it should make a significant difference to the job prospects of those who have completed or are currently completing probation in Scotland."