The study examined the perception of affordances for vertical jumping-and-reaching and horizontal jumping by children with and without kung fu training. Two tasks were used: a horizontal jump, where children estimated and performed their maximum forward jump from a standing position, and a vertical jump, where they estimated and attempted to touch a ball at the highest reachable point during a running jump. Kung fu athletes (10.81 ± 0.83 years) were compared to children with no competitive athletic experience (10.56 ± 0.72 years). Results showed that kung fu-trained children had superior actual performance in both tasks. Constant and absolute errors from actual performances and judgments on the tasks were calculated and analyzed separately. The kung fu athletes tended to underestimate in both tasks, whereas non-athletes tended to overestimate in the horizontal task. For kung fu athletes, the absolute error between tasks was not significant, but for non-athletes, the absolute error for the horizontal task was higher than for the vertical task. The study concluded that kung fu experience was associated with a general tendency for children to underestimate their jumping ability, suggesting changes in the perception of athletic ability and opportunities.