Fungi of the genus Aspergillus are found everywhere in the natural environment; they cause invasive pulmonary aspergillosis (IPA), an infectious complication common in immunocompromised individuals, which has a mortality rate of up to 90% in patients with hematological malignancy. The first line of defense of innate immunity is the recognition of Aspergillus conidia by dendritic cells or alveolar macrophages. DC-SIGN is an integrin directly involved in this recognition; its degree of expression in immune cells and its functionality may be partly determined by genetic variations. The objective of this study was to determine whether the presence of polymorphisms of a single nucleotide in the DC-SIGN gene increases the risk of invasive pulmonary aspergillosis. For this purpose, the variants DC-SIGN-139A/G (rs2287886) and DC-SIGN+11C/G (rs7252229) were analyzed In 314 subjects (152 patients with hematologic malignancy and 162 healthy controls). Of the 152 hematologic cancer patients, 81 were diagnosed with demonstrated invasive pulmonary aspergillosis per EORTC/IFICG criteria, and the remaining 71 patients had no symptoms of the infection. An association was found between the variant DC-SIGN-139(A/G) and resistance to IPA. Carriers of the allele A (A/A + A/G) were significantly more resistant to the infection than patients with the G/G genotype (p = 0.0574). Analysis of the serum concentration of the galactomannan antigen supported the hypothesis that this polymorphism may be implicated in the susceptibility to suffer invasive pulmonary aspergillosis. Although the difference was not statistically significant, carriers of the allele G had a higher frequency of positive galactomannans than subjects with the genotype A/A (p = 0.1921). These results suggest that the variant DC-SIGN-139(A/G) in the DC-SIGN gene promoter influences the risk of invasive pulmonary aspergillosis and may therefore be used as a genetic biomarker to stratify patients according to risk.