Sunflower seed harvested from diseased plants in a Verticillium nursery in Manitoba, surface-sterilized and plated on potato sucrose agar, gave rise to colonies of Verticillium albo-atrum Reinke and Berth. Microsclerotia of the organism were confined to the hull and testa of the infested seeds. The fungus was not found in any portion of the seed inside the testa. Approximately 50 per cent of the infested seeds germinated on the agar plates; the rest apparently were dead. Symptoms typical of Verticillium infection developed in sunflower plants in a plot on clean soil sown with seed harvested from diseased plants in a Verticillium nursery. No diseased plants were found in adjacent plots sown with seed from healthy plants.Failure to isolate the pathogen from seed taken from typically diseased plants in a farm field near the Verticillium nursery may signify that seed infestation occurs only under favorable circumstances. The factors predisposing to such infestation are not yet known. Lack of consistency in isolation of the pathogen from seed taken from diseased plants from various sources parallels the contradictory results obtained by workers studying seed dissemination of V. albo-atrum in other crops.