Abstract Ecological patterns of tropical myxomycetes have been subjected to study only during the last decade. An exhaustive analysis of an extensive dataset for a single tropical country is lacking. For this reason, the present study was designed with the primary objective of examining the ecological distribution patterns of myxomycetes in Costa Rica. A database that includes historical records was compiled, and factors such as forest type and substratum preference were analyzed in an effort to understand these patterns at both the macro- and microenvironmental levels. Microenvironmental parameters that may drive abiotic preferences were analyzed. The ecological distribution of species showed a complex pattern; however, elevation seemed to be a key factor in determining the distribution of the group of species analyzed. In the same way, nonwoody substrata seemed to represent the most important factor explaining the niches occupied by myxomycetes in lowland regions of the country.