The present study investigated the performance-predicting factors of a simulated cross-country (XC) skiing sprint competition on roller skis, on a slow surface. Sixteen elite male XC skiers performed a simulated sprint competition (4x850m heat/20 min recovery) using V2 skating technique on an indoor tartan track. Heat velocities, oxygen consumption and peak lactate were measured during or after the heats. Maximal skiing velocity was measured by performing a 30-m speed test. Explosive and maximal force production in the upper body was determined by bench press. Subjects also performed maximal anaerobic skiing test (MAST) and 2x2 km double poling (DP) test. The maximal velocity of MAST (V_MAST) and velocities at 3 (V₃), 5 (V₅), 7 (V₇) mmol∙l^-1 lactate levels in MAST were determined. In the 2x2 km test DP economy (VO_2SUBDP) and maximal 2 km DP velocity (V_DP2KM) were determined. The best single performance predicting factors for the sprint performance were V_DP2KM (r = 0.73, p<0.01), V₇ (r = 0.70, p<0.01) and VO_2SUBDP (r = -0.70, p<0.01). Faster skiers in sprint simulation had a higher absolute VO₂ (l·min^-1) (p<0.05–0.01) during sprint heats, as well as higher anaerobic skiing power (V_MAST, p<0.05) and better anaerobic skiing economy (V₃, V₅, V₇, p<0.05 – 0.001) than slower skiers. Faster skiers were also stronger in bench press, with regard to both absolute (p<0.01) and relative (p<0.05) values. In addition, anaerobic characteristics seem to be of importance at the beginning of the XC skiing sprint competition whereas the aerobic characteristics become more important as the XC skiing sprint competition progressed. This study indicates that sprint skiers should emphasize sport-specific upper body training, as well as training skiing economy at high speeds.