Fusarium oxysporum is a well-known soil-borne and ubiquitous fungus. The species includes a high diversity of saprophytic and pathogenic populations. The phytopathogenic ones are subdivided into formae speciales according to their host specificity. The forma specialis cyclaminis (FoCy) is causing Fusarium wilt only on cyclamen. It causes damages during the entire production line and can raise more than 50 % losses. FoCy is considered as the more destructive pathogen on cyclamen. To achieve a better understanding of the disease and a more efficient and eco-friendly way of control, we aim at finding a specific molecular marker allowing for early detection and quantification of the pathogen and at selecting efficient BioControl Agents (BCA). We first created a collection of 74 strains of putative FoCy from international collections and diseased cyclamens. We also collected other strains of F. oxysporum, other Fusarium species, saprophytic and soil-borne fungi, and other fungi known to be pathogenic on cyclamen. The identity of the putatively FoCy strains was assessed by sequencing the Internal Transcribed Spacer (ITS) and the Elongation Factor 1 α (EF) and by testing their pathogenicity. Their genetic diversity was characterized by combining data from the EF and the InterGenic Spacer (IGS) sequencing and provided 7 cluster types. One strain was taken from each cluster and used for searching for a common specific marker by Random Amplified Polymorphic DNA (RAPD). So far, one band appears specific for 6 cluster types and one is specific of the 7th cluster type. SCAR (Sequences Characterized Amplified Region) primers are being designed. Primers specificity and sensitivity will be estimated using the whole strains collection. To complete this prophylactic tool, we are currently evaluating the antagonistic activity of several commercial BCA to select the most efficient one to control FoCy.