In Turkey, a mass measles immunization campaign was initiated in 1985, and the decision was made to administer the first of the measles vaccinations at nine months of age instead of 12-15 months. Following the campaign there was a decrease in the number of measles cases seen in the Outpatient Department of Istanbul University Children's Hospital in 1986 and 1987; however, after 1987 an increase was observed in measles cases, which continued until 1993. In order to investigate the current measles epidemics, we reevaluated the measles cases seen in our Outpatient Department from 1986 to 1993. We also investigated the vaccination status and the hospitalization and mortality rates of measles cases in the epidemics of 1988 and 1993. Since 1988 (except 1989) a significant increase (412-1375 percent) has been observed in measles cases, and between 1986 and 1993 more than half of all measles cases were in children older than four years of age. In 1988 and 1993 we found that most vaccinated measles cases were also in this age group, but the rate of complications and hospitalization among the vaccinated cases was lower compared to those who were not vaccinated.