In this study, we investigated problems on the management of dysplasia on the basis of our clinical data obtained in the past ten years. In addition, we also examined the biological significance of protooncogene expression and human papilloma virus (HPV) infection in the initiation and promotion of dysplasia. Among 540 cases of dysplasia we have managed, 48.8% of the cases of mild, moderate and severe dysplasia which we followed up for more than 6 months regressed, and 24.1% of the cases progressed. The cure rate for laser therapy based on the follow up for 6 to 96 months was significantly high (97.9%) in 342 cases treated by the cone method, and low (89.5%) in 38 cases treated by the vaporization method. Preoperative histological findings confirmed 60.5% of postoperative findings, and several early cervical carcinomas were found in preoperative cases of dysplasia by laser conization. Among 28 cases (8.2%) of incomplete excision, 24 cases (85.7%) regressed spontaneously. On the other hand, the positive rate of immunostaining of epidermal growth factor receptor (EGF-R) and c-myc oncogene product (c-myc protein) increased from mild or moderate to severe dysplasia, and the positive rate for EGF-R was significantly high (80.0%) in the progressive group. The positive rate for HPV genome was quite low (16.0%) in dysplasia. Among them, EGF-R was most associated with the prognosis of dysplasia. These results suggest that laser conization should be performed for many cases of dysplasia because of the preoperative possibility of the existence of early cancer, and EGF-R is also useful in determining the necessity for therapy for dysplasia.