In spite of the increasing number of myxomycete studies in the tropical Southeast Asia over the last decades, many forest patches are still left unexplored for the region, in particular in the Philippine archipelago. Thus, an assessment of myxomycete diversity, occurrence, and composition was carried out in forest fragments from two municipalities of the province of Laguna, Philippines. From the 12 established 5 m × 5 m plots, a total of 240 moist chamber cultures were prepared for this study and yielded 42 myxomycete species belonging to 14 genera. Rarefaction curves and several heterogeneity indices revealed higher species diversity in Los Baños than in Calauan. Moreover, the taxonomic diversity index also showed that the taxonomic diversity of myxomycete in Los Baños is more intuitively diverse than in Calauan. In terms of community analysis between the two municipalities, it showed that myxomycete communities clustered between different microhabitats. High values of coefficient of community and percentage similarity indices possibly implicates that spore dispersal in forest fragments in closer proximities may cause high number of shared species (60%). With an addition of Cribraria lepida as a new record for the country, this study now updates the myxomycete profile for Laguna, Philippines.