The objective of the paper was to determine the impact of moisture and rotational speed of threshers on the process of crushing of lupine seeds. Raw material was led to four levels of moisture from 8 to 14% every 2%. The studies were carried out on the laboratory hammer mill with the use of variable speeds of mill hammers within 5500-7000 rot∙min−1. The studies that were carried out proved significant relations (p<0.05) between the analysed process variables and energy consumption and susceptibility of seeds to crushing. It was stated that along with the increase of the rotational speed, a reduction in the drop of the average dimension of particles of mill takes place. Along with the increase of moisture of lupine from 8 to 14% a unit energy of crushing increases on average by approx. 83%. It was proved that the susceptibility ratio of seeds to crushing increases along with the increase of raw material moisture. Such relations were determined for all investigated rotational speeds of hammers.