Mannose-binding lectin is an important constituent of the innate immune system, the serum levels of which are greatly affected by polymorphisms of the MBL2 gene: three polymorphisms in exon 1, as well as nucleotide variations in the promoter region of the gene, have been associated with protein deficiency and some infectious and autoimmune disease. The aim of this study was to investigate a possible association between MBL2 gene polymorphisms in patients who have developed type 1 diabetes during childhood and adolescence. We evaluated MBL2 gene polymorphisms in 214 children and adolescents with type 1 diabetes and compared them with a healthy control group, finding significant differences in genotypic and allelic frequencies (p = 0.004 and p = 0.0008, respectively). Our results suggest that patients with type 1 diabetes possessing the 0 allele have a higher risk for developing type 1 diabetes during childhood and adolescence, and that this risk factor is not related to age at diagnosis.