Wheat (Triticum aestivum) is a commercially important cereal in Mexico; however, there have been reports of head blight in Guanajuato, Mexico, which have been attributed to Fusarium species. This study hypothesized that wheat head blight is caused by several species of Fusarium. Therefore, the objective was to evaluate the frequency and pathogenicity of Fusarium species in wheat spike in the state of Guanajuato. For this purpose, plots sown with wheat in the 20 wheat-producing municipalities were sampled. The strains were isolated until pure cultures were obtained, and they were morphologically and molecularly characterized; the sequences obtained were registered in GenBank. The pathogenicity and severity of the disease were assessed on flowering wheat plants of the Cortázar S94 variety at the flowering stage. The results were evaluated 10 days after inoculation and the data were analyzed using ANOVA statistical analysis. Ten Fusarium species were found, with F. oxysporum (35.57 %), F. verticillioides (12.5 %), and F. proliferatum (11.53 %) being the most common. All Fusarium strains were pathogenic, with F. oxysporum being the most severe, followed by F. proliferatum. In conclusion, it was possible to identify the causal species of wheat head blight in the state of Guanajuato.