Although studies of myxomycetes in plantations have started to appear in the last few years, some agroecosystems with homogenous vegetation remain unexplored. This holds true for rice agroecosystems. A study comparing the occurrence of myxomycetes in organic and conventional rice fields in the province of Cotabato was carried out in rice farms in the municipalities of Kabacan and Midsayap. Ground and aerial litters were randomly collected from rice fields to set up moist chamber cultures. Three cosmopolitan species of myxomycetes are reported in this study, namely <em>Arcyria cinerea</em>, <em>Diderma hemisphaericum</em>, and <em>Perichaena depressa</em>. Moist chambers set up with rice litter substrates from organic fields showed significantly higher percentage yield than moist chambers with the substrates from conventional rice farms. This study is the first to explore the distribution of myxomycetes in rice agroecosystems of the Philippines and to compare different farming practices.