It has been suggested that visual contrast sensitivity and contour integration functions exhibit a late maturation during adolescence. However, the relationship between these functions has not been investigated. The aim of this study was to assess the development of visual contrast sensitivity and contour integration in 152 healthy volunteers aged between 5 and 30 years. The results revealed a significant maturation of contrast sensitivity at low spatial frequencies (0.5, 1.2, and 1.9 cycles/degree) and contour integration. The largest developmental step was observed for both contrast sensitivity and contour integration tasks when the 5-8-year olds were compared with the 9-11-year olds. There was a significant correlation between the development of low spatial frequency contrast sensitivity and contour integration. These results raise the possibility that the development of low spatial frequency processing may affect attentional mechanisms, which may have an impact on early contour integration.