An understanding of growth and maturation is important for any aspiring youth soccer coach. Tanner’s works are seminal in this field and these have provided most data using globally recognised methodological approaches. Some of these concepts have been used to assess youth soccer players. Furthermore, over the past 10 years developments in technology such as dual-energy x-ray absorptiometry (DEXA), magnetic resonance imaging (MRI) and near infrared spectroscopy (NIRS) have led to an upsurge in scientific advancement. New technologies are enabling scientists to develop a better understanding of factors that affect growth and performance. Sport and exercise scientists interested in how growth affects performance are beginning to use these technologies to help sports coaches and teachers apply sound scientific principles in their practice.