This study describes a successful Plasmodium vivax sporozoite infection in Aotus lemurinus griseimembra . Twenty-eight naive or previously infected monkeys, either splenectomized or spleen intact, were inoculated intravenously or subcutaneously with Plasmodium vivax sporozoites of the Salvador I strain or with two wild isolates (VCC-4 and VCC-5; V ivax - C ali- C olombia). The monkeys were successfully infected regardless of the parasite strain, spleen presence, or inoculation route and showed prepatent periods that ranged from 16 to 89 days. Only one monkey inoculated intravenously failed to develop parasitemia. Since immune protection against malaria pre-erythrocytic forms is mediated by both helper and cytolytic T cells that may home in the spleen and P. vivax cultures are not yet available; the use of spleen-intact A. lemurinus griseimembra , susceptible to both adapted and non-adapted strains of P. vivax sporozoites, is a valuable model for evaluation of pre-erythrocytic vaccine candidates.