Aim: The aim of this study was to investigate the determinants of the healing failure of diabetic foot ulcers (DFU) in people with type 1 diabetes (T1DM). Methods: This retrospective study included 50 individuals with T1DM and DFU treated in a tertiary care-center with a regular follow-up for at least 6 months. Laboratory measurements, clinical assessments and classification of DFU were collected at the baseline. Moreover, glucose measurements were collected by 10-days 7-points self-monitoring of blood glucose and used to retrieve glycemic metrics. The study population was divided in 2 groups, according to the outcome [Healed (H) group (n=28) and Not-Healed (NH) group (n=22)]. Results: Compared with H group, NH group had significant higher levels of HbA1c (p=0.037), tot-cholesterol (p=0.011), LDL-cholesterol (p=0.039), microalbuminuria (p=0.034), CRP (p=0.047), and lower levels of 25-OH vitamin D (p=0.013). Moreover, the proportion of neuropathy (p=0.012) and DFU infection (p=0.005) was significantly higher in the NH group, whereas the H group was significantly older (p<0.001) and with a higher proportion of peripheral artery disease (p=0.016), revascularization (p=0.006) and lipid-lowering therapy intake (p=0.021). Furthermore, among glucose variability parameters, the coefficient of variation (CV) was significantly higher in the NH group (p=0.035). The multiple logistic regression analysis identified CV [(1.02–20.12), p=0.047] and neuropathy [(1.19-25.66), p=0.029] as independent predictors of healing failure. Conclusions: In a population with T1DM and DFU treated in a tertiary-care center, high CV and neuropathy were related to healing failure after 6 months follow-up.