This study further tests the general assumption that skeletal development is more sensitive to socioeconomic factors than dental development in a sample of modern immature Portuguese skeletons (N = 41) of known sex, age, and socioeconomic background. Skeletal development was assessed from skeletal maturation of the knee and dental development was assessed from schedules of tooth formation. Discrepancies between physiological age (skeletal and dental age) and chronological age were used as a measure of developmental status. A positive score indicates that physiological age is in advance of chronological age, whereas a negative score indicates the reverse. Two socioeconomic groups, one of low and the other of high socioeconomic status, were created based on the occupation of the father and on the place of residence, and developmental status was compared between the two socioeconomic groups. Results confirm previous studies by showing that dental development is less affected by environmental insults than skeletal maturation. While socioeconomic differences in skeletal maturation range from 1.20 to 1.22 years (15–18% of chronological age), socioeconomic differences in dental maturation range from 0.51 to 0.53 years (4–9% of chronological age). Compared to a previous study, results also suggest that skeletal maturation is more affected than skeletal growth. Additionally, an adaptation of the radiographic atlas of skeletal development of the knee is proposed for use with dry skeletal material. Am J Phys Anthropol, 2011. © 2010 Wiley-Liss, Inc.