The matter was transferred to the Makhado Magistrate's Court, where they would apply for bail on Friday.
They remain in custody, police spokesperson Ronel Otto said.
Albert Mawela, Edmond Ramokgopa, Moshumi Moseamo and Vivo Richard Masodi were arrested on Sunday while they were allegedly planning to hunt rhino in the Waterpoort area, near Makhado.
The first man was taken into custody when he went to their vehicle to retrieve ammunition.
After his arrest police, with the help from local farmers, caught the other two on the farm.
The fourth man, Masodi - an employee on the farm - was caught late on Sunday evening.
He was found in his room on the property.
"A hunting rifle, an axe, as well as the vehicle used by the suspects were confiscated," Otto said.
They allegedly fired shots, but no rhino were harmed.
They were facing charges of attempted rhino poaching, trespassing and possession of an unlicensed firearm.