Abstract Lambson, B., Smyth, A., and Barker, D. C. 2000. Leishmania donovani: Development and characterisation of a kinetoplast DNA probe and its use in the detection of parasites. Experimental Parasitology94, 15–22. The polymerase chain reaction is used increasingly widely for the diagnosis of both cutaneous and visceral leishmaniasis and for the identification of asymptomatic carriers in the population in endemic disease areas. The use of complex-specific hybridisation probes in conjunction with the polymerase chain reaction increases the specificity as well as the sensitivity of the diagnostic procedure as it discriminates between different infecting Leishmania species. A minicircle kinetoplast DNA probe, B4 Rsa, which hybridises to all members of the Leishmania (L.) donovani complex has been identified and characterised. It is a segment of a minicircle highly conserved in Bangladeshi and Indian L. (L.) donovani isolates.