Assessing learners' performance is crucial as it informs about learners' achievement levels in addition to their strengths and weaknesses, not only in face-to-face but also in online teaching. The study aimed at investigating the challenges faced by language teachers in assessing learners during online teaching and to offer some suggestions regarding language assessment courses in teacher training programs. The study adopted a qualitative approach to data collection and analysis. The participants included 22 language teachers aged between 24 to 48. Of these teachers, 8 were male, while the rest were female. Their teaching experience varied from 2 to 25 years, with an average of 11.8 years. The data was based on the responses of the participants during semi-structured interviews. The participants were asked to attend ZOOM meetings to be held, considering their availability. The interviews lasted 10 to 25 minutes. The results of the study indicated that the challenges faced by the participants included five major themes: Assessment type, assessment item formats, support, previous training (assessment literacy), and academic integrity. Several suggestions were offered considering online testing and assessment literacy and language assessment courses in teacher training programs.