In connection with the depletion of fossil fuel resources and negative impact of their combustion products on the environment, there is a need to search for renewable energy sources. Biomass of plant origin that can be used e.g. for the production of solid biofuels in the form of briquettes or pellets is one such source. The article presents an analysis of qualitative characteristics of briquettes made from the selected plant materials using a hydraulic piston briquette machine. The study used the following materials: wheat straw, rape straw and camomile waste. During the briquetting process the adopted moisture of the crushed material was: 10.0; 13.0 and 16.0%, while the operating pressure of the briquetting piston: 6.0; 8.0 and 10.0 MPa. During the study the following values were determined: particle size distribution, length and mass of the produced briquettes as well as their specific density and mechanical strength. Depending on the briquetted raw material and studied factors, the specific density of the pellets and their mechanical strength increased with the increasing moisture and briquette machine's pressure. There was a statistically significant effect of the raw materials moisture and briquetting pressure on the qualitative properties of briquettes under study.