This paper is an effort to promote the adoption of longitudinal designs and mainstream them in communication research in Africa, especially Nigeria. The concept and types of longitudinal research are explained. The reasons why longitudinal approaches are indispensable to communication research are discussed. This task is crucial since the trend among African and Nigerian researchers is to consign longitudinal approaches to the sidelines while overly emphasizing cross-sectional designs. The paper takes a cursory journey down the road of media effects theory, among others, to show that the cumulative effects of the media can better be researched with longitudinal systems than with crosssectional ones. Three empirical works are reviewed to show the weaknesses of using only cross-sectional methodologies to study every kind of communication problem while strengthening the case for longitudinal systems. The recommendations expose researchers to the threat of extinction that longitudinal designs face as well as motivate the longitudinal habit.