Hemivertebra is a rare congenital spinal disorder where only one side of the vertebral body develops, leading to deformation of the spine, such as scoliosis or kyphosis. Previous reports suggest that the diagnosis may be based on antenatal sonographic examination after 14 weeks. We present the sonographic features of a fetus with solitary hemivertebra at 13 weeks' gestation confirmed by postmortem babygram, magnetic resonance imaging (MRI) and pathological examination. It shows that the condition may manifest in the first trimester of pregnancy.