Good results of in vitro study of anti-HIV effects of JinHuang, a Chinese herbal medicine led to in vivo study of safety and efficacy among asymptomatic HIV infected individuals. It was a prospective open study of 21 asymptomatic HIV infected Thai volunteers. Twelve and 9 were female and male, respectively, with mean age of 29.24 +/- 3.94 years. JinHuang preparation, 6 capsules and 2 bottles of liquid formula orally three times a day, was given on an outpatient basis initially for 6 months. Regular close monitoring and follow-up were done. The side effects reported included : increased bowel movements (81%), vague taste, and smell of drug after initiation (52%). No serious adverse event related to JinHuang was detected during study. No significant changes in terms of log viral load and CD4 count were observed after 6-months' duration. Most of the patients felt that the quality of life was better in terms of better appetite, good sleep and healthy during study participation, however, these were subjective.