Background: Children with Down syndrome (CDS) have low health-related physical fitness levels. Since, bursts of high-intensity constitute a major part of children's daily activities, it is important to determine the levels of anaerobic fitness in CDS. Aim: The aim of this study was to estimate the differences in anaerobic performance between CDS and typically developing children (TDC). Methods: Anaerobic performance was assessed in a group of twelve 8-16 year old CDS and their performance was compared to thirteen age-matched typically developing peers. The anaerobic performance of all children was measured using a field test-muscle power sprint test where children were asked to run six- 15 m sprints. The outcome measure was mean power (MP) that represented the average power output of all sprints. Results: The MP for CDS was 50.1 (25.03-75.2) W in comparison to 145.6 (114.6-176.7) W in TDC. Conclusions: The levels of anaerobic fitness are lower in CDS than in TDC. Implications: The rehabilitation strategies should emphasize strength training in adjunct to aerobic training to improve physical fitness in CDS.