In a statement, Broadband Minister Stephen Conroy identified the first six ISPs as Primus Telecommunications, Tech 2U, Webshield, OMNIconnect, Netforce and Highway 1.
Customers of participating ISPs will be able to choose whether they want to be included in the pilot trial, Conroy said, although he noted that all WebShield customers already receive a filtered service.
The Government did not rule out bringing other ISPs such as iiNet and Optus into the trial.
It has been reported that iiNet and Optus wanted to participate to disprove the technical feasibility of the proposal.
"Arrangements for the first phase of the live pilot have been finalised with six ISPs while consultations continue with a number of other ISPs that have applied to take part," Conroy said.
"The Government is committed to take an evidence-based approach to implementing its cyber-safety policy and these trials will provide valuable information to inform our approach.
"The Government is well aware of technical concerns about ISP filtering and that is why we are conducting a pilot, to put these claims to the test."
Testing with each ISP will take place for a minimum six weeks once filtering equipment has been obtained and installed.
It will look at the efficiency and effectiveness of a range of technical solutions, as well as other issues such as the ease of circumvention, impact on internet speeds and user experience, Conroy said.