To identify issues of sample mix-ups, various molecular techniques are currently used. These techniques, however, are time consuming and require experience and/or DNA sequencing equipment or have a relatively high risk of errors because of contamination. Therefore, a quick and straightforward single nucleotide polymorphism (SNP) profiling assay was developed to link human tissues to a source. SNPs are common sequence variations in the human genome, and each individual has a unique combination of these nucleotide variations. Using potentially mislabeled paraffin-embedded tissues, DNA was extracted and SNP profiles were determined by real-time polymerase chain reaction analysis of the purified DNA using a selection of 10 commercially available SNP amplification assays. These profiles were compared with profiles of the supposed owners. All issues (34 in total) of potential sample mix-ups during the last 3 years were adequately solved, with six cases described here. The SNP profiling assay provides a quick (within 24 hours), easy, and reliable way to link human samples to a source, without polymerase chain reaction postprocessing. The chance for two randomly chosen individuals to have an identical profile is 1 in 18,000. Solving potential sample mix-ups will secure downstream evaluations and critical decisions concerning the patients involved.