Over half of accusations made against teachers and teaching assistants by pupils in Wales turned out to be false, malicious or unfounded.
Figures for the last five years obtained by BBC Wales found 55% of 312 allegations were later dropped.
Teaching unions say that to try to deal with the problem, more action should be taken against those who make false or malicious claims.
The Welsh government said it is updating its guidance on the issue.
It said it will include advice on what consideration governing bodies should give to taking action against accusers.
But it added that it was important to take children’s claims seriously and not deter pupils with genuine complaints from coming forward.
ALLEGATIONS MADE AGAINST TEACHERS AND TEACHING ASSISTANTS FROM 2006-2011
|Council||Teachers and assistants accused||Malicious, false or unfounded|
|Anglesey||8||Figures not available|
|Caerphilly||Figures not available|
|Ceredigion||Figures not available|
|Conwy||2 (figures for 2009-10)||2|
|Flintshire||6||Figures not available|
|Gwynedd||15 (figures for 2009-10)||15|
|Neath Port Talbot||2 (figures for 2009-11)||1|
|Pembrokeshire||7||Figures not available|
|Powys||13 (figures for 2009-11)||7|
|Rhondda Cynon Taff||23||6|
|Swansea||Figures not available|
|Torfaen||18 (figures for 2009-11)||18|
|Vale of Glamorgan||37||26|
|Total for Wales||312||174|