X-rated footage was visible to staff and journalists inside the Indonesian parliament for 15 minutes before security staff were able to turn off the stream, local media report. The TVs are used to provide information on the day's political schedule.
It comes ahead of an 11 August deadline for local internet service providers to start blocking online pornography.
It is unclear if the incident at the House of Representatives is in any way connected.
Local media reports that the pornographic images were taken from an adult website that is banned in neighbouring Singapore and Malaysia.
The deputy speaker of the House apologised for the incident.
Correspondents say the move to block online porn, which was ordered by Indonesia's Information Minister Tifatul Sembiring last month, has been generally welcomed in the Muslim-majority democracy of 240 million people.