This study investigates citation patterns between 2017 and 2020 for preprints published in three preprint servers, one specializing in biology (bioRxiv), one in chemistry (ChemRxiv), and another hosting preprints in all disciplines (Research Square). Showing evidence that preprints are now regularly cited in peer reviewed journal articles, books, and conference papers, the outcomes of this investigation further substantiate the value of open science also in relation to citation-based metrics on which the evaluation of scholarship continues to rely on. This analysis will be useful to inform new research-based education in today’s scholarly communication.