Banana streak virus (BSV) is an important limiting factor to the subsistence production of banana in Uganda. The aim of this project was to assess the variation of Ugandan isolates of BSV in order to provide both information and diagnostics for the associated project (R7529) on the epidemiology of the virus. Fifty nine samples of leaves and suckers were taken from 30 farms at 14 sites across the banana producing region of Uganda. Other samples of infector and recipient plants from the epidemiology experiments were provided by the associated project. A new technique was developed for BSV purification and virus preparations were made from the 47 field samples for which there was sufficient material.