Painful injury and noxious stimuli increase activity in nociceptive pathways at all ages. Due to the plasticity of the developing nervous system, there is potential for early life events to produce a long-term ‘memory’ with changes in the structure and/or function of nociceptive pathways that can influence future pain response. Effects vary with the type and severity of injury, and the age at which it occurs. Recent evidence form laboratory and clinical studies will be discussed, with a focus on surgical injury and subsequent persistent post-surgical pain.