Sugarcane disease diagnostics plays an instrumental role in biosecurity and disease management. There has been considerable investment in improving disease diagnostic tests for some exotic and established sugarcane pathogens in recent years. However, for some important pathogens, the diagnostic test development had not been upgraded for many years. This paper describes the progress in upgrading diagnostic tests for nine of these pathogens/diseases: Fiji leaf gall (Fiji disease virus), Leaf scald (Xanthomonas albilineans), Sugarcane mosaic virus, Maize chlorotic mottle virus, Sugarcane-infecting mastreviruses, Sugarcane yellow leaf virus, Red leaf mottle (Peanut clump virus), Ramu stunt virus, and Sugarcane-infecting phytoplasma (white leaf, grassy shoot and green grassy shoot diseases). The literature was reviewed for the most recent diagnostic tests, and new diagnostic tests were developed by Sugar Research Australia including LAMP and qPCR. Published and new diagnostic tests were compared side-by-side with the existing diagnostic test. In order for a test to be suitable as a replacement it must be shown to be more sensitive, as specific, be able to detect known variants, easy to carry out, have potential for field application, and suitable for use in the SRA quarantine laboratory. In most cases this was possible, and the chosen upgraded diagnostic tests are to be trialled in 2022.