Late‐medieval and post‐medieval writings report that scurvy was a widespread condition in medieval and early historical Poland. Archaeological and historical data indicate that the diet of children was based on foods poor in vitamin C and contained small amounts of raw plant products. Also, historians emphasise that in medieval and post‐medieval Poland, there were seasonal fluctuations in food availability, frequently accompanied by poor harvests. Both resulted in long periods of poor nutrition, which affected children most severely. The aim of this study was to investigate skeletal manifestations of scurvy in subadult remains from medieval and post‐medieval Poland. Following standards described by Ortner and colleagues, anatomical sites pathognomonic of scurvy in subadults (<17 years) were assessed for abnormal porosity and hypertrophic bone among skeletons excavated from three sites: Ostrów Lednicki (dated to the 11th–14th centuries AD), Cedynia (10th–14th centuries AD) and Słaboszewo (14th–17th centuries AD). In total, 3.6% of all examined children were found to bear traces of vitamin C deficiency. The prevalence of scorbutic lesions was 4.5% for Cedynia, 2.6% for Ostrów Lednicki and 3.6% for Słaboszewo. The majority of affected children were less than 7 years of age. Scurvy was likely more widespread in the living populations than it appears from the calculation of skeletal markers, because some individuals might have recovered or died before obvious traces became apparent. Also, in some children, scurvy might not have reached an advanced stage, identifiable in the skeletal material. The prevalence of scurvy reflects not only dietary patterns but also food storage and preparation techniques adopted in the Polish territories during the Middle Ages, which contributed to low intakes of vitamin C. Copyright © 2015 John Wiley & Sons, Ltd.