We report on a case of de novo direct duplication for the distal part of chromosome 3p: 46,XY,dir dup (3) (p25-->pter). At the age of 4 years and 7 months, the boy presented with moderate growth and mental retardation, muscular hypotonia, hypoplasia of the left kidney, a short neck, and a square-shaped face characterized by a broad and flat nasal bridge, slight epicanthus, and full cheeks. So far, only a few cases with such a small distal 3p duplication have been described, and none of them has a de novo direct duplication for this region. In our patient, dysmorphic signs are less impressive, and developmental delay is relatively moderate.