Abstract. Given the problems encountered in westernized countries with the laboratory diagnosis of malaria, namely sensitivity of the conventional methods and detection of mixed infections, a polymerase chain reaction (PCR)–based diagnosis has been developed and routinely used. The PCR used two sets of primers to simultaneously detect any infection due to the genus Plasmodium, or to the species P. falciparum. The PCR results were available within six hours. Five hundred twenty-nine patients were tested, of whom 136 were found positive by the PCR, and only 104 by the quantitative buffy coat (QBC™) method. The 32 discrepancies were analyzed on the basis of the clinical data, and technical, molecular, and sequencing findings to ascertain the p...