The nurses were supposed to be paid the money in December last year.
Nurses in Tharaka-Nithi County have threatened to go on strike if they are not paid leave and uniform allowances within 21 days.
Kenya National Union of Nurses (Knun) county chapter chairman Fabian Marigu on Wednesday said they were supposed to be paid the money in December last year.
"We request for the payment of the annual leave and uniform allowances in the next 21 days failure to which we will go back to the old dark days of unrest," Mr Marigu said.
Mr Marigu said the regional government has not yet fully implemented the agreements signed to end the strike last year.
He added that some nurses whose contracts were terminated in April 20 this year have continued working without any directive from the administration.
"The silence from county government is disturbing, especially after we signed a court consent," he said.
Health executive Gichuyia Nthuraku said they are willing to pay out the allowances but the funds are insufficient.
"We have been able to pay all the pending allowances that we inherited from the former regime and we are ready to pay the leave and uniform allowances once we get money," Dr Nthuraku said.
He urged the nurses to be patient.