The children were evacuated to the playground at around 9:15am and parents were asked to collect them.
A spokesman for North Yorkshire Police said:
We were called at 8.25am on Tuesday 29 May 2012, to reports of a security alert at Rossett Acre primary school.
Officers from North Yorkshire Police fully assessed the situation and there is no threat to pupils and staff at the school.
A spokesperson for North Yorkshire County Council said:
Rossett Acre Primary School in Harrogate has been closed for a second time today following the receipt of a second malicious communication.
Children were not allowed into the school on arrival and were subsequently sent home by the headteacher.