Congenital rickets is considered a rare disease entity in the newborn period. Hypocalcemic seizure due to congenital rickets has been reported, but this symptom generally appears at the earliest at the end of the first month of life. A congenital rickets case presented unusually with seizure on the first day of life is reported, and the continuing occurrence of the disease with serious consequences even at the beginning of life is emphasized. Despite improved prenatal care offered today, congenital rickets still occurs. It seems that vitamin D deficiency in the neonate secondary to maternal deficiency should be a consideration for the pediatrician or neonatologist caring for newborns. Physicians should be aware of risk factors that can trigger the development of this condition and should be alert to the signs of congenital rickets in order to commence appropriate treatment and prevent complications such as seizure occurring as early as shortly after birth.