The Correctional Services Department will appeal the judgment against former president Jacob Zuma.
The High Court in Pretoria declared the decision to grant Zuma medical parole unlawful.
It was also set aside.
The court ordered that the former president returns to prison to finish his 15-month jail sentence.
The Correctional Services Department says it is convinced that another court may arrive at a different conclusion.
It says the court sadly misinterpreted the Correctional Services Act and erred in its ruling.
Zuma was granted medical parole by former prisons boss Arthur Fraser in September.
Zuma’s lawyers have also filed court papers for leave to appeal the judgment.