The tsunami of December 2004 inundated the Thai coastline of the Andaman Sea to a distance of up to 5 km with a maximum wave height of 11 m. The force of the surge was devastating to the point that tens of thousands of humans were killed, whereas the effect on non-human biota, including insects, remains largely unreported. We sampled lentic (pond) habitats within the area directly affected by the tsunami, and other reference ponds further inland. Samples were taken five months after the tsunami, which marks the end of the dry season. Sampling was repeated in August during a lull in the rainy season. By five months, many ponds in the tsunami area already had substantial freshwater recharge through rainfall, and conductivity measured from 400 to 20,000 microSiemens. All ponds sampled had a freshwater insect fauna re-established, the diversity of which differed depending on conductivity.