A number of studies have indicated that cyclin E plays an important role in a variety of neoplastic processes. In our study we evaluated cyclin E1 expression and the possible prognostic value of this protein in neuroblastic tumors in children. Cyclin E1 expression was investigated by means of immunohistochemical analysis of 25 neuroblastic tumor tissue samples. We found a significant correlation between high cyclin E1 expression and deaths due to neoplastic disease. The mean values of cyclin E1 indexes in fatal cases were twice as high as in other cases. The results indicate that high cyclin E1 expression may have prognostic importance in neuroblastic tumors in children.