The efficacy of pyrimethamine-sulfadoxine in the treatment of uncomplicated falciparum malaria in young children of a malaria holoendemic area in rural Burkina Faso is reported. Of 28 children treated with a standard single dose of pyrimethamine-sulfadoxine and followed-up over 14 days, only one Late Treatment Failure and four Late Parasitological Failures were observed, all with low-grade parasitaemia. In this area of very restricted use of pyrimethamine-sulfadoxine, the drug appears to be still sufficiently effective in the treatment of malaria. These findings provide further evidence for the justification of continued use of pyrimethamine-sulfadoxine as a second-line treatment for malaria in Burkina Faso.