In May 2004, following reports from local farmers of a devastating new banana disease, three authors of this paper visited Masisi District, 72 km north-west from Goma in North Kivu Province, Democratic Republic of Congo Republic, and diagnosed banana bacterial wilt caused by Xanthomonas campestris pv. musacearum. Symptoms included: progressive yellowing, wilting and blackening of leaves; yellow or brown vascular streaks throughout the plant; pockets of pale yellow bacterial ooze in airspaces within leaf bases; premature ripening and internal discoloration of fruits; and shrivelling of male inflorescence buds. ABB banana genotypes appeared to be the first to be infected, and matooke clones (AAA-EA group) the last. Affected stools do not always die; new suckers emerge and these initially appear healthy but usually become infected from the mother plant, rarely surviving to the flowering stage. The epicentre of the outbreak in Masisi was devastated, with total loss of yield and an alarming impact on food security. Biochemical and molecular characteristics of yellow pigmented bacterial isolates confirmed the identity of the pathogen.