This article presents an analysis of the orthographic errors found in university students' asynchronous digital writing. A university and a society belonging to the twenty-first century require students and professionals who can use their language correctly in any context, device and mode of communication. The research was based on a sample of 1237 digital interactions in discussion forums and emails between students of the National University of Distance Learning on subjects related to academic work. We applied a descriptive quantitative methodology by means of a statistical and lexicometric analysis of the written texts and multiple regression analysis, related to four independent variables: gender, studies, interlocutor (professor/student), and digital device (fixed, mobiles) and three orthographic sub-levels (punctuation, accentuation and spelling). The results show that there is considerable room for improvement in the orthography of university students' asynchronous digital writing. A total of 71.3% of errors were not conditioned by independent variables but by ignorance of the orthographic rules or incorrect use of the language.