This communication was to share the efforts made in developing the fully online courses in medicinal chemistry during the educational disruption due to the coronavirus disease 2019 (COVID-19) pandemic. In the academic year 2020, the online course was implemented for the first time at the Faculty of Pharmacy, Silpakorn University, Thailand. Various online teaching strategies were integrated, raising the question of whether the developed online courses would deliver similar learning outcomes to the traditional classroom. At the end of each semester, the teaching assessment report was conducted and evaluated in 4 parts: part 1, evaluation of lecturer; part 2, student's self-evaluation; part 3, learning outcome development after studying the course; part 4, appropriateness of class environment and equipment. Overall, student responses toward parts 1--3 in the online class were as satisfactory as those in the previous on-site class. Lower scores toward part 4 were observed in the online class. In addition, student performance in terms of grade distributions between the on-site and online classes was different. On-site students earned the highest proportion of A grades, whereas online students earned a higher proportion of B+'s to F's. While the pandemic persists and the need for online courses remains, we hope that this communication will provide some educational insight and strategies to help in the ongoing efforts to adapt and establish more successful online courses.