Dysplasia of the uterine cervix is a recognized precancerous condition. Because of the observed ability of retinoids to suppress various cell lines in vitro, a number of clinical studies have examined the effect these agents have on cervical dysplasia, with the object of developing a means of chemoprevention of cervical malignancies in women at risk. Three cervical cancer chemoprevention trials with Retinamide II (RII) have been conducted at the Cancer Institute, Chinese Academy of Medical Sciences, Beijing, China. A pilot study used RII to intervene in cases of precancerous cervical dysplasia. Twenty-seven women with mild, moderate, or severe cervical dysplasia, pathologically confirmed, were treated by RII suppositories, 10 mg QD, given intravaginally for 6 months (each course lasting 3 months). The results indicated that after the second course, the overall response rate was 96.29% and the complete response rate was 88.89%. In general, side effects were mild. A little cervical and vaginal irritation was well tolerated. In the second double-blind study, patients with precancerous cervical lesions were randomized into two groups, one treated with RII suppository intravaginally and the other with a placebo, once daily for 50 days in two courses. Precancerous lesions in 68.76% of patients in the treatment arm disappeared, with an overall effective rate of 74.29% after two courses of treatment with RII. Its curative effect was approximately that of laser beam radiation and electrocautery (P > 0.05), and differed significantly (P < 0.01) from that of traditional antiinflammatories. RII can be a major measure in prevention and treatment of cervical cancer in high-incidence areas in China. In the third trial, we are conducting a randomized double-blind study placebo controlled, in a high-incidence area of cervical cancer (Xiang-Yuan county, Shang Xi Province, China). At present, the patients are being followed up and the study will be completed after 2 years.