Phytoplasma infections are regularly reported worldwide, and concerns about their threats on agricultural production, especially in relation to global climate change, are increasing. Sensitive and reliable detection methods are important to ensure that propagation material is free of phytoplasma infection and for epidemiological studies that may provide information to limit the extent of phytoplasma diseases and to prevent large-scale crop losses. The detection method described here uses LNA chemistry in real-time PCR. It has been developed and validated for use on potatoes, and its sensitivity and specificity make it suitable for use in postentry potato quarantine and initiation of potato nuclear stocks to ensure that material is phytoplasma-free.