Text-based communication is one of the substantial ways of spreading scientific information. While the content and contextual aspects of written words have been widely researched, the impact of font characteristics on text perception is an almost blank page. The following study deals with the influence of serifs on the evaluation of online-presented scientific abstracts. Yet there is only evidence for faster reading times when texts are presented in sans-serif fonts, although the opposite is stated in parts of the literature. The present work examines if the presence or absence of serifs also have an impact on the appraisal of scientific texts when all other important font characteristics do not change. For this purpose, 188 university students participated in an online experiment and rated different aspects of scientific abstracts as well as of the research outlined in the abstracts. The results show that missing serifs led to increased reading speed. However, and in contrast to the perceptual fluency hypothesis, the presence of serifs had a positive effect on all evaluation dimensions. The results of a second study with 187 participants also indicated that reading fluency counteracted the liking of texts. Implications for future studies and media production are discussed.