M.Tech. (Homoeopathy) / The purpose of this study is to determine the effect of the homoeopathic complex formula consisting of , Echinacea angustifolia tincture, Baptisia tinctoria tincture and Thuja occidentalis D1 on circulating leukocytes. These medicinal plants have immune enhancing properties and an effect on leukocytes. Leukocytes play an important role in the body's defence system. 54 volunteers participated in a randomised double blind placebo controlled trial. An initial full blood count before treatment served as a base-line control for each volunteer. A total of 15ml of the medication placebo was administered over 3 hours. After the last dose, a further three blood samples were drawn at 90 minute intervals. Blood analysis included a differential leukocyte count. The trial was conducted over a single 6 hour period. The homoeopathic medication caused a decrease in circulating leukocytes, specifically lymphocytes. The efficacy of this medicationas an immunostimulant should be confirmed on a larger study sample.