Fungal pathogens tend to accumulate within styroblock containers, which are reused to produce successive crops of container-grown seedlings. Most nurseries treat reused containers by immersing them in hot water for varying time periods. The efficacy of radio frequency waves (RFs) to reduce levels of selected groups of fungi within styroblock containers was evaluated. RFs were effective only on containers that had been wetted in warm water prior to treatment. RFs were not effective on dry containers. Fusarium proliferatum was the most commonly encountered potentially-pathogenic fungus isolated from containers. Seven other species of Fusarium and two species of Cylindrocaipon were also isolated from containers. Common fungal saprophytes on containers included Trichoderma and Penicillium spp. Although wet RF treatment was as effective as hot water immersion, such treatments may be much more expensive due to high costs of RF equipment.