Abstract1H NMR spectroscopy of brain extracts was used to investigate the metabolic changes that take place during development of the neonatal rat brain. Data were obtained over the range 1–21 days. The concentration ofN‐acetylaspartate rose by a factor of 9 during this period, the most rapid rise occurring after day 9. The total creatine concentration rose from days 1–21, with a large increase between days 1 and 5. Taurine concentration rose until day 5, then fell from days 5–21. The concentration of choline‐containing compounds fell during the 21 day period. The results are discussed in relation to brain development and conventional biochemical data. A major conclusion in relation to spectroscopy of children is that interpretation of changes seen in disease will require adequate data from age‐match