There is scientific data to support the existence of a two-way relationship between diabetes and periodontitis, with diabetes increasing the risk for periodontitis, and periodontal inflammation negatively affecting the diabetic status. Our study aims to investigate the expression of MMP-7, -8, -9 and -13 in the gingiva of the young patients with aggressive periodontitis (AP) and type 1 diabetes mellitus (T1D). Gingival biopsies were harvested from five adult patients aged 19-29 years with T1D+AP with moderate (three cases) to severe (two cases) forms of AP and from four adult patients aged 18-28 years with moderate AP without T1D. The MMP-7 immunoreaction was positive in the five cases with T1D+AP with different staining patterns. The MMP-8 immunostaining was positive in all cases. The reaction was more intense in cases with T1D+AP, especially in those with severe periodontitis. The MMP-9 immunoreaction was present in all the structures of the gingival mucosa with different intensity, being frequently present surrounding the blood vessels of the chorion. In most of the patients, reaction to MMP-9 was intense, localized at the level of the cells in the superficial chorion and very rarely at the level of some dispersed cells in the connective vascular islands. MMP-13 was present in all cases, but it was more intense in the two cases with T1D+AP with probing depth (PD)>6 mm when it had similar patterns as MMP-9 staining and in one case with AP when the staining was observed strictly in the lamina propria associated with moderate chronic inflammatory infiltrate. The expression of MMP-7, -8, -9 and -13 in the gingiva of the young patients with aggressive periodontitis and T1D was positive in all studied cases supporting the hypothesis that both are inflammatory diseases with common pathogenic mechanisms involving inflammatory mediators and may be possible biomarkers of disease status.