Standards and management at a Welsh-medium primary school earmarked for closure in Carmarthenshire have been criticised by inspectors.
There was a protest earlier this year over possible closure
Mynyddcerrig is the first in the county to need "special measures" following a visit by inspection body Estyn.
Parents are fighting plans to shut it as part of education reorganisation.
But while inspectors said behaviour and attendance were good, there were "many important shortcomings" across a range of subjects and in school leadership.
The 18-pupil school is one of three in the upper Gwendraeth Valley that may be merged as part of Carmarthenshire Council's £110m education plan.
Earlier this year youngsters from Mynyddcerrig joined pupils from nearby Bancffosfelen and Llangyndeyrn schools on a protest walk to the top of the village mountain.
In a report following an inspection in March, Estyn said that "leadership and management of the school are ineffective" and "standards are low in the vast majority of subjects inspected."
It also said pupil's achievements were much lower than Welsh Assembly Government targets.
The governing body has been given 45 days to show how it intended implementing Estyn's key recommendations.
The school is one of two in Wales needing "special measures"
As a school needing "special measures" it will be inspected each term rather than every four or five years to monitor progress.
It is currently one of only two in Wales in the category; the other is in Powys.
A further five are classed as having "serious weaknesses" - schools where the education minister can intervene to take over the running of the school if they do not improve.
An acting head teacher has taken at over Mynyddcerrig as the usual head is on sick-leave.
Carmarthenshire's director of education, Vernon Morgan, said the report was "disappointing".
"An action plan is being drawn-by the LEA, governors and staff to address the issues raised," he added.
The report however did praise the school for education for the under fives, its attendance and behaviour record and special needs support.
The quality of teaching was at least satisfactory in 82% of lessons observed.
In a statement the school governors said they welcomed the report's "positive and supportive comments on a range of issues across the school".
"We as a governing body together with the LEA will address the areas which require attention," it added.
It said an action plan would be drawn up and regular meetings held with parents to update them on progress.
The statement said the governors were committed to ensuring: "that broad, balanced, differentiated and relevant education is delivered to those pupils at the school and those yet to start."