Several studies have demonstrated differences in Google Scholars' and Web of Science's coverage of citing publications. In this paper, we examine whether citation data retrieved from Web of Science and Google Scholar reflect women's and men's scholarly impact differently. Our study is based on a sample of 200 randomly selected U.S. authors in economics- and sociology-related research areas. Our results illustrate noteworthy gender disparities in the per-paper citation rates across the two databases. In sociology, we find that women benefit more than men, when impact assessments are based on data from Google Scholar, while the opposite is the case in economics. If our results prove to be robust in a larger data-set, based on a more exhaustive matching of documents, they illustrate how the selection of data-sources can have consequences for how individual scholars are assessed, e.g. in tenure or grant review evaluations.