In 1992, Indonesia provided troops for the United Nations Transitional Authority in Cambodia, and supported Cambodian membership to ASEAN in 1999.

The relationship between ancient Indonesia and Cambodia dated back from the kingdom of Chenla and Javan Sailendra and also Srivijaya; it was mentioned that king Jayavarman II had resided for some times in Java during the reign of Sailendras,[2]: 35  and in 802 declare sovereignty of Cambodia from Java and proclaimed himself as universal monarch thus started the Angkor period.

There must had been exchanges of travelers, if not missions, between the Khmer Kingdom and the Sailendras in Java, transmitting to Cambodia not only ideas, but also technical and architectural details.

Both nations have similar archaeological heritages that are held as UNESCO World Heritage Sites; the temple of Borobudur and Angkor Wat, both are proclaimed as sister sites in January 2012 during ASEAN Tourism Forum in Manado, North Sulawesi.

[6] Indonesia with its experience on Borobudur restoration projects, has lent its expertise on Angkor preservation efforts.

[10] Both Cambodia and Thailand trust Indonesia as a fair and impartial observer to solve intra-ASEAN disputes.