Measles remains a leading vaccine-preventable cause of child mortality worldwide. The incidence has increased recently in some areas. The authors retrospectively analyzed the epidemiological and clinical characteristics of 2473 measles patients in Shanghai from 2000 to 2009. There were 1909 measles cases during 2005-2009 (group II), whereas only 564 cases were reported during 2000-2004 (group I). In total, 60.87% patients in group II were younger than 9 months, which was significantly higher than that in group I (35.28%; P < .001). More complications, death cases, and less atypical rashes were found in recent years. In addition, 2181 of all the 2473 patients (88.19%) and 1112 of 1328 hospitalized children (83.73%) had not been vaccinated; most of them were immigrants. The results indicated that the rising number of immigrants accounted for the increased measles morbidity in Shanghai. The tendency of more young patients and increased complications suggest that some adjustments might be needed in vaccination administration and therapeutic strategy.