Given the importance of prior knowledge on adaptable decisionmaking in sport, tactical knowledge of 109 youth soccer players (8-12 years) and its relationship with age, experience and expertise was studied using The Soccer Tactical Knowledge Test. Moderate magnitude significant differences were observed depending on the age and experience in federated competitions of the players (p <, 05; r <, 40), although results were mixed. The expertise correlated significantly with declarative (rho =, 350; p <, 01), procedural (rho =, 446; p <, 01) and tactical knowledge of the players (rho =, 446; p <, 01). Findings suggest that age and experience would not be as decisive over tactical knowledge as other variables not studied: teaching methods, formal instruction, or coach formation. It is necessary more research to examine whether specific formation on tactical problems concepts could improve decision-making in sport and in youth soccer.