the aim of this study was to evaluate the detection of new cases of leprosy in prudentópolis, state of paraná, from 1998 to 2005. additionally, we investigated the age group and predominant clinical form of leprosy cases. data were obtained from clinical-epidemiological records of confirmed leprosy cases that were notified in the information system for notifiable diseases, between 1998 and 2005. over this period, 222 leprosy cases were notified, of which 63% presented the multibacillary form, with predominance of the virchow clinical form, thus indicating a process of intense disease transmission. among these leprosy cases, 35% of the patients were at an economically active age (31 to 45 years old). these indicators showed that there was a high level of bacillus circulation in the community, considering that one risk factor for infection by the bacillus mycobacterium leprae is contact with untreated individuals who have the multibacillary form. this is despite the drastic reduction in leprosy prevalence over the last two decades, through the implementation of polychemotherapy and other preventive measures.