Cutaneous leishmaniasis is a major tropical infection of public health importance caused by a number of vector-borne Leishmania protozoa species. Evidence supports a highly complex etiology. Environmental, parasite and host factors determine pathogenesis, and result in a diverse clinical spectrum of disease. Disease susceptibility, clinical course, prognosis and therapy response are highly variable, suggesting a genetic basis. Epidemiological studies have demonstrated familial aggregation, and family and association studies have identified HLA and non-HLA gene associations. Further progress in susceptibility gene identification for leishmaniasis would require genome-wide scans and candidate gene-association studies in large cohorts. Correlation between host genotype and therapy response has important pharmacogenetic implications, especially as current therapies for leishmaniasis are inadequate and progress in new drug development has been poor.