Many galactosaemics appear to have neuropsychological and/or linguistic problems in spite of dietary treatment. Because the neonatal screening program in Norway does not include galactosaemia, we have re‐examined Norwegian galactosaemics. Of 16 known patients, 8 patients participated in the study. They had been diagnosed between 2 and 11 weeks of age, and were between 9 months and 19 years old at the time of this study. All had very low or 0 activity of galactose‐1‐phosphate uridyl transferase. As part of the study all were examined neurologically, and had an age‐appropriate developmental/IQ test, an ABR and an EEG, and a comprehensive psycholinguistic evaluation. The three youngest patients had normal developmental/IQ tests, while the five older patients had IQ scores in or below low range of normal. The majority had delayed language development and three patients were classified as having verbal dyspraxia. ABR and EEG showed mild pathology in the oldest patient only. Galactosaemia appears to be associated with significant risks of developmental and language delays in this unscreened population.