AbstractMoisture content and temperature are two important process parameters that greatly influence the quality of biomass pellet fuels. The moisture content of raw material was varied at five levels (8%, 10%, 12%, 14%, 16%) to test its effect on water hyacinth pellet density and diametric compression strength. The experimental conditions included a compressing force of 6 kN, hammer mill screen size of 2 mm, and temperature of 100 °C. Five temperature conditions (80, 90, 100, 110, and 120 °C) were studied under the same conditions and 12% moisture content. In these conditions, the optimal moisture contents for water hyacinth pellet density and diametric compression strength were 12.2% and 11.5%, respectively, and the optimal temperatures were 100.4 °C and 104.3 °C, respectively.