AbstractPeripheral blood mononuclear cells (PBM) from normal vervet monkeys(Cercopithecus aethiops)were examined for blastogenic responses to concanavalin A (ConA), phytohemagglutinin (PHA), and pokeweed mitogen (PWM). The mitogen stimulated PBM in a dose‐dependent manner. Response to ConA was apparently higher than for the other two mitogens. Cell density and mitogen concentration were critical parameters for optimal lymphocyte proliferation, an observation in line with that reported for other mammalian species. Depletion of an adherent cell population probably of monocyte/macrophage lineage from vervet PBM gave higher proliferative responses to both ConA and PHA, but the response without adherent cells to ConA was greater than the response without adherent cells to PHA. This latter finding is in contrast to what has been reported in many other specie