Congenital disorders of glycosylation (CDG) are a group of disorders involving a defect in the synthesis of oligosaccharides. Oligosaccharides are fundamental for protein stability and cellular communication and are present in almost every cell in the human body. A defect in the synthesis of oligosaccharides can result in multisystemic effects. Congenital disorders of glycosylation are classified into type I and type II disorders, each with subgroup classifications. All CDGs are autosomal recessive disorders, with CDG type I being the most common. This article will explore both types of CDG, their clinical presentation, diagnosis, and management.