Background: One of the most common diabetes-related reasons for hospitalization is diabetic foot infections (DFIs), which are a significant cause of morbidity. Osteomyelitis (OM) is a regrettable side effect of a DFU infection that spreads via soft tissues into the underlying bone. Aim: to estimate the percentage of fungal infection in the pathogenesis of diabetic foot lesions and determine if adding antifungal drugs may affect the prognosis. Patients and methods: A prospective cohort study, including 100 diabetic patients with infected diabetic foot ulcers with underlying osteomyelitis. Two wound swabs and bone biopsies were taken from the depth of the ulcer consisting of necrotic slough and granulation tissue, and carried immediately to the microbiology laboratory, at Assiut University to be examined. Once the fungal culture study is positive, oral fluconazole 150 mg every other day for 2-3 weeks was started for the patient with a maximum duration of two months or when healing occurs. Results: The current study revealed that all the studied patients had positive bacterial growth. Out of them, 22 (22%) patients had mixed fungal and bacterial growth while the majority (78%) had only bacterial growth. Candida is the most common pathogen isolated in fungal OM. Conclusion: Regarding the treatment of OM caused by fungi, there is no clear consensus. In the current study, patients with a lengthy history of foot ulcers were more likely to develop fungal foot infections. Furthermore, it's critical to stop the spread of resistance because there aren't any other effective antifungal treatments for treating severe fungal infections.