The aims of the present study were to develop a method for classifying slalom skiing performance and to examine differences in mechanical parameters. Eighteen elite skiers were recorded with three-dimensional kinematical measurements and thereafter divided into a higher (HP) and lower performance group, using the ratio between the difference in mechanical energy divided by the mass of the skier and section entrance velocity (Δemech/vin). Moreover, the skiers' velocity (v), acceleration (a), center of mass turn radii (RCM) and skis' turn radii (RAMS), ground reaction forces (GRF) and differential specific mechanical energy [diff(emech)] were calculated. v and diff(emech) were different between the performance groups (P<0.001 and <0.05), while no inter-group differences in RCM, RAMS, a and GRF were observed. A relationship between RAMS and diff(emech) was demonstrated (r=0.58; P<0.001). The highest GRFs were related to the lowest diff(emech) and a was related to GRF (r=−0.60; P<0.001). The Δemech/vin predicted the performance over short course sections. The HP skiers skied with a higher v and a similar range of diff(emech). We suggest that shortest RAMS and the highest GRFs should be reduced in elite slalom in order to increase performance.