Phytoplasmas are plant pathogenic microorganisms. The Yellow leaf syndrome (YLS) had been first detected and described in Hawaiian sugarcane plantations. In this work, several surveys on sugarcane plants in Hawaiian Islands were done for sugarcane yellow leaf phytoplasma (SCYLP). Two types of phytoplasmas were found in Hawaiian sugarcane cultivars mainly sugarcane white leaf phytoplasma (SCWL). Sugarcane samples were obtained also from other countries including Thailand, Cuba and Egypt. Our research showed that nested-PCR is better than real-time PCR for low titer phytoplasma detection. In this study, phylogenetic analysis of the detected phytoplasma strains was also performed. Ultra-structural changes, of the leave anatomy and cytology by phytoplasma infection and cytological location of phytoplasma were determined by the transmission electron microscopic (TEM) studies. Insect vectors of phytoplasmas are phloem feeders. However, our tests confirmed that black sugarcane aphids were unable to transmit the phytoplasmas. Hot water treatment has been proposed to cure plant material from phytoplasmas. We examined in this work which appropriate hot water treatment, is recommended.