Vascular wilt caused by the fungus Fusarium oxysporum f. sp. dianthi is the most important disease on carnation in Colombia. Although the use of resistant varieties is an economical and promlsmg method for the management of the disease, some varietiss do not behave in a similar way in different farms, and there are evidences of the variability ofthe pathogen. The objective of this research was to determine the presence of physiological races, of the pathogen in the Bogota Plateau. One hundred isolates of the pathogen were obtained in 49 farms from different varieties of standar and miniature carnation affected by the disease. The isolates of the fungus were inoculated in four differential varieties: Duca, Pink Calypso, Raggio di Sole and San Remo. Ninety seven isolates corresponded to the race 2, that is the most frequent race in the world and the other three isolates belong to the race 4, that is a race prevalent in Italy.