There is a risk of error associated with all forensic science conclusions. However, no proper studies have been conducted in any of the forensic sciences to estimate the rate at which forensic science conclusions are wrong. As a result, jurors and other consumers of forensic science information are left to speculate about what those error rates might be. The present paper provides data from an online study (n = 210) about what jury-eligible people (“jurors”) think the false positive error rates are for five types of forensic science evidence (DNA, fingerprints, bite marks, microscopic hair, and handwriting). Jurors’ median estimates range from a high of 1 in 100,000 (handwriting) to a low of 1 in 1,000,000,000 (DNA). The significance of these estimated false positive error rates is discussed.