The script find_amplicons.pl predicts all the amplicons that should be generated by a list of (multiplexed) primers mixed with a set of sequences. This PCR-simulating script lists amplicon sequences, their length and position, and the forward+reverse primer combination to yield each product, as well as a summary file of the fragment length distributions enabling a quick assessment of how well each target sequence can be discriminated based purely on amplicon length patterns. We used this script to check whether some viral primer sets are predicted to generate amplicons from the human genome.