The COVID-19 pandemic has a risk of causing a learning loss in the education sector. If this condition continues, it may lead to the declining in the ability and the quality of students. This research aims to evaluate the risk of learning loss for Medical students in online learning process during the COVID-19 pandemic. This research is a quantitative-descriptive research with a total sampling of 172 students from Medical Program. The primary data is obtained by filling out a questionnaire through a validated Google form. The results of the research show that there is a decrease in the student's understanding during the problem based learning activities as much as 29.6%. The Clinical skill lab activities are decreased by 62.8%. The change from offline learning to online learning has caused the decrease in these activities that resulting in an ineffective learning, thus leading to the risk of learning loss. If the condition continues, learning loss may occur as a result of online learning during the COVID-19 pandemic.