Mekhong Full Moon Party (Thai: 15 ค่ำ เดือน 11; RTGS: Sip Ha Kham Duean Sip Et; literally, "The 15th Day of the 11th Month") is a 2002 Thai comedy-drama about the Naga fireballs that arise from the Mekong at Nong Khai on the full moon in October.

The film takes a semi-documentary approach to its subject, examining the phenomenon and its accompanying festival, which draws thousands of people to Nong Khai each year, as well as providing a glimpse at Isan culture, Thai folklore and such practices as eating insects.

Khan knows the truth: Having grown up as a dek wat at a Buddhist temple across the river in Laos, he helped the temple's abbot and the monks there to create fireballs and plant them on the bed on the Mekong.

The temple's abbot, Luang Poh Loh, seeks Khan out and begs him to once again help with the planting of the fireballs.

This sets up a conflict between science and religion that threatens to change the annual celebration.