The online form of education has been intensively used worldwide for many years and gains additional importance in emergencies such as the COVID-19 pandemic, natural disasters, and wars, when it becomes the dominant form of class delivery. Besides the recent pandemic, the world is now facing wars and the threat of their spread, making the research on the impact of fear and anxiety on human behavior relevant. The student population already faces increased depression and anxiety, which affect their behavior; therefore, it is crucial to investigate their impact on academic behavior in an online context during disruptions to the educational process. Consequently, this research focuses on analyzing student satisfaction and their academic effort and performance with online education during the COVID-19 pandemic. The empirical part of the study involves investigating the impact of instructor quality, fear of COVID and students’ anxiety on student satisfaction with online classes and students’ effort and performance at the higher education institutions in Croatia during the COVID-19 pandemic. A quantitative study was conducted on a sample of 359 respondents, students from two universities in Croatia. Results showed that the quality of instructor has a positive effect on student satisfaction and that student satisfaction positively affected students’ academic effort. Results also suggested that emotional reaction in fear of COVID-19 affected anxiety reported by students, but emotional fear reactions to COVID-19, and anxiety alike, did not affect academic effort of students, nor their satisfaction with online classes.