Vegetative incompatibility is a fungal allorecognition system characterized by the inability of genetically distinct conspecific fungal strains to form a viable heterokaryon and is controlled by multiple polymorphic loci termed vic (vegetative incompatibility). We have identifieded the first vic locus in Botrytis cinerea using a bulked segregant approach. Two adjacent, highly polymorphic open reading frames, Bcvic1 and Bcvic2, which encode predicted proteins that contain domain architectures implicated in vegetative incompatibility. Bcvic1 encodes a putative serine esterase domain, a NACHT family of NTPases domain, and several Ankyrin repeats. Bcvic2 encodes a putative syntaxin protein containing a SNARE domain such proteins typically function in vesicular transport.