Objective: To examine whether polymorphic alleles at these two loci are involved in the susceptibility to visceral leishmaniasis (VL) in Moroccan children. Methods: We have genotyped polymorphisms by PCR-restricted fragment length polymorphisms in 102 patients with VL, 92 asymptomatic carriers [positive skin test delayedtype hypersensitivity (DTH+)] and 40 healthy controls (negative skin test delayed-type hypersensitivity), with no history of Leishmania infection. Results: Regression analysis showed no significant association between polymorphisms of tumor necrosis factors-??when comparing VL and DTH + group (P > 0.05). The associations were detected between VL and negative skin test delayed-type hypersensitivity for the heterozygote genotype (P = 0.021), the recessive model: 1/2 + 2/2 (P = 0.044) and the minor allele 2 (P = 0.019). The resistance to VL was found to be under the recessive model 1/2 + 2/2 of tumor necrosis factors-β, when comparing VL and DTH + group (odds ratios: 0.558, 95%; confidence interval: 0.316-0.987; P = 0.044). Conclusions: These results must be regarded to preliminary but suggestive that further study with larger populations is worthwhile