The goal of this study was to measure the neurophysiological and cognitive functions of a sport-concussed child and to longitudinally assess the recovery pattern. An 8-year-old girl suffered a concussion while playing soccer. Visual evoked potentials (VEPs) were recorded at 7 weeks pre-injury and 24 h, 7, 22, 32 and 55 weeks post-injury. A neuropsychological assessment performed at 24 h post-injury reveals cognitive impairments, mainly attentional, that resolved within 22 weeks. VEPs and spectral analyses confirm the presence of cortical impairments up to 1 year post-injury, especially affecting vigilance and attention, which were reflected in school performance.