Municipal waste is a highly diverse category of waste. It can depend on various factors such as a settlement type, the level of communal infrastructure, the living standard of population, a tourist season etc. The diversity of municipal waste is also affected by the composition of waste. Municipal waste mostly contains organic and inorganic waste, but hazardous waste can also be found. Organic waste consists of food waste, paper and cardboard, plastic packaging, textiles, leather etc. Inorganic waste consists of glass and various packaging waste. In WMC Kaštijun, municipal waste is subjected to various treatment procedures and one of the output fractions is a small fraction of residual waste which is suitable for disposal in a bioreactor landfill. The aim of this paper is to determine the basic physical parameters of the fine fraction of waste from WMC Kaštijun. The conducted analysis shows that in the sample taken from small waste fractions plastic and biodegradable waste predominate and that there is no hazardous waste. From an engineering point of view, it can be pointed out that due to the high content of organic matter, the mechanical parameters of the waste will change over time. Also, significant subsidence in the body of the landfill can be expected. Due to the high proportion of fibrous components, Kolsch’s shear strength model of waste is probably applicable.