A retrospective sero-epidemiological investigation of Peste des petits ruminants (PPR) was carried out in Ngorongoro district, situated in northern part of Tanzania and bordering Kenya. The study involved collection of field information from 101 respondents who own goats and sheep in four villages which had experienced a ‘rinderpest-like’ syndrome in domestic small ruminants between first suspected cases of PPR in 1995 and official confirmation of the disease in Tanzania in 2008. A total number of 198 serum samples from goats and sheep collected in 1998 and 2004 for different research projects or suspected disease investigation were retrieved from the Veterinary Investigation centre (VIC) Arusha and subjected to competitive ELISA test for detecting antibodies to PPR virus. Findings of this study suggest that PPR was in northern Tanzania at least four years before official confirmation and reporting based on clinico-pathological grounds, local field-based reports from livestock field officers and District Veterinary Officer. The seroprevalence of PPR from 198 serum samples analysed was 12.6% with the serum samples collected from suspected PPR cases showing significantly (p=0.000) higher seroprevalence (71.4%) than that in samples collected for investigation of other diseases (5.7%). Interviewed farmers were aware of PPR including clear description of clinical signs of the disease. Although farmers were aware of efforts made to control the disease, only 32% of them had their animals vaccinated against PPR. The low vaccination coverage suggests continued prevalence of PPR in the study area. It is concluded that there is limited capacity with respect to veterinary disease surveillance, reporting and control of transboundary and emerging diseases which need to be addressed in the country.