A senior medical advisor to Papua New Guinea's National Aids Council Secretariat says not all HIV/AIDS patients can get the latest anti-retroviral treatment.
The World Health Organisation has given 600,000 US dollars to fund the procedure which is new to PNG.
The drugs are designed to stop the advancement of the virus into the body.
But Dr Joachim Pantamari says the drugs will only be given to patients in extreme stages, as they have strong side effects and because of the high costs.
"This anti-retroviral drugs or sometimes they are referred to as hard or hyper- active retroviral therapy. They are quite toxic. Once you submit a patient on these treatment regimes they have to be on this drug all their lifetime and therefore in a country like PNG, we will have some problems, so we won't submit all patients on this anti retro viral drugs."
Dr Pantamari says the drugs may cause liver damage, skin problems and destroy fat tissues in the face.
He wants all potential patients who want the treatment to register at clinics, and to inform family members of the programme.