With the emergence of CoVid-19, many educational pillars have been altered from conventional ways to online solutions. The educational assessment has been administered in online environments despite all encountered challenges. This descriptive study aimed to explore online assessment strategies and uncover the online assessment challenges that were confronted. The sample consisted of the academic staff at the College of Education at Sultan Qaboos University. A mixed-method approach was adopted for data collection. A survey was used to collect quantitative data from 60 academic staff. Furthermore, semi-structured interviews were conducted with four academic staff. The quantitative data was analyzed by calculating the means and standard deviations, while the qualitative data was analyzed using content analysis and thematic analysis. The study's findings showed that academic staff's most applied online assessment strategies were individual projects, presentations, discussions, written assignments, group work, research proposals, and time-constrained exams. However, the academic staff rarely applied peer assessment, fieldwork, journal writing, annotated bibliography, and fact sheets. In addition, the study found some challenges when applying online assessment such as learners' refusal to turn on cameras, heavy teaching loads, cheating, the long time required for developing online assessment's instruments, impersonation/dishonesty, assessing practical experiences, plagiarism, grades' inflation, assessing group's work, academic integrity and a large number of students per section. Based on the findings, some educational implications and recommendations were suggested to develop the online assessment field. The study recommended applying various alternative assessment strategies embedded in the online course activities to reduce the likelihood of cheating and increase the validity and reliability of the overall assessment process. Also, it is suggested that academic staff need to design and adapt assessment tools that require students to demonstrate skill and knowledge acquisition. Moreover, it is important to reduce teaching workload and the number of learners per section so that academic staff can follow each individual's learning progression per section, providing the necessary constructive feedback to benefit from the online courses.