Abstract Background The process of elimination of intracellular pathogens, such as Leishmania , requires a Th1 type immune response, whereas a dominant Th2 response leads to exacerbated disease. Experimental human zinc deficiency decreases Th1 but not Th2 immune response. We investigated if zinc and copper levels differ in different clinical forms of leishmaniasis, and if these trace metals might be involved in the immune response towards the parasite. Methods Blood was collected from 31 patients with either localized cutaneous (LCL), mucosal (ML) or visceral (VL) leishmaniasis, as well as from 25 controls from endemic and non-endemic areas. Anti- Leishmania humoral and cellular immune response were evaluated by quantifying specific plasma IgG, lymphoproliferation and cytokine production, respectively. Plasma levels of Cu and Zn were quantified by atomic absorption spectrophotometry. Results A significant decrease in plasma Zn was observed in all three patient groups (p LCL>ML) immune response. Ex vivo production of parasite-induced IFN-γ was negatively correlated to plasma Cu levels in LCL (r = -0.57, p = 0.01). In vitro , increased Cu levels inhibited IFN-γ production. Conclusions 1. Zn deficiency in VL and ML indicate possible therapeutic administration of Zn in these severe forms of leishmaniasis. 2. Plasma Cu positively correlates to humoral immune response across patient groups. 3. Environmentally or genetically determined increases in Cu levels might augment susceptibility to infection with intracellular pathogens, by causing a decrease in IFN-γ production.