The aim of this paper was to describe the over time prevalence of autism from 2000 to 2007 in Taiwan, with particular focus on the age, gender, prevalence and causes. We analyzed data from the public web-access information collected by the Department of Statistics, Ministry of the Interiors, Taipei, Taiwan. The data included: (1) the physically and mentally disabled population by age and severity level; (2) the physically and mentally disabled population by cause; and (3) the Taiwan general population by age. The registered number of people with autism drastically increased from 2062 to 7207 (increase rate=249.5%), and the male/female ratio of autism was 6.0-6.6 from 2000 to 2007. The autistic cases increased significantly, particularly in children between 6 and 11 years of age, occupying about 43.9-49.5% of the autistic population. The reported prevalence of each age group, aged 0-5 years was 2.4-7.8/10,000, aged 6-11 was 5.0-17.3/10,000, and aged 12-17 years was 2.1-10.4/10,000 from year 2000 to 2007. The main cause of autism was congenital (48.5-58.0%), followed by disease (9.5-31.1%) or other (20.0-32.7%). An increase in prevalence would suggest the need for more attention and funding of services for children with autism. (Contains 1 figure and 4 tables.)