Citrus species grown in Japan are affected by several viruses and viroids, including satsuma dwarf virus, citrus vein enation virus, citrus exocortis viroid, and other citrus viroids. Recently, a comprehensive review was made on the occurrence, history, and research of the following three major citrus viruses in Japan: satsuma dwarf virus, citrus tatter leaf virus (apple stem grooving virus), and citrus tristeza virus (Iwanami 2022). As a sequel, this study reviews the occurrence, history, and research development of citrus viroids as well as minor citrus viruses in and around Japan.