A descriptive epidemiologic study on the detection of new leprosy cases was conducted in São Luís, Maranhão, Brazil, from 1993 to 1998. A database was created for the purpose, covering 2,796 reported cases. General detection rates were calculated, as well as specific rates by gender, clinical type, and age group. Linear, exponential, geometric, and log adjustment models were performed to analyze time trends in the disease. An increase in detection was observed, involving mostly female and paucibacillary cases, mainly of tuberculoid leprosy. The increase in detection was most evident in the 15 to 19 year-old population. The percentage of detection under 15 indicated the need for active case search in this group.