Abstract A description is provided for Pseudomonas viridiflava . Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Wide variety of hosts. Initially reported on bean ( Phaseolus vulgaris ), but since reported as naturally occurring on at least 31 different species in 14 different families (see for example 53, 395; Billing, 1970). By inoculation a further 30 host species, including 5 extra families, have been found to be susceptible (60, 1802: 9: 695). DISEASE: Originally isolated from reddish brown circular spots on bean pods, but a variety of symptoms have since been reported. Wilkie et al. (1973) reported leaf spot of pumkin and lupin, leaf rot of cauliflower, leaf blotch of passion fruit, stem rot of poppy, internal stem rot of tomato, a wet rot of leaves, stipules and stems of pea, panicle rot of grape, and blossom blight of chinese gooseberry ( Actinidia chinensis ). GEOGRAPHICAL DISTRIBUTION: Possibly world wide. Currently known from Kenya (50, 1060), Uganda (NCPPB 1474), Iran (NCPPB 2012), Japan (59, 1887), Australia (NSW, Qd., 63, 3168), New Zealand (53, 395), France (52, 2974), W. Germany (57, 739), Hungary (NCPPB 389), Netherlands (NCPPB 2502), Spain (54, 5140), Switzerland (Original Descr.), UK (50, 1060), USA (California 61, 749; Florida 14: 565; New York 12: 71; Pennsylvania 62, 4928). TRANSMISSION: Apparently exists as a common epiphyte which gains entry through wounds, as a secondary organism, or when the plant has been predisposed by unfavourable conditions when these, or other conditions also favour the bacterium.