Background: Coronavirus disease 2019 (COVID-19) pandemic management depends on public acceptance of vaccines and vaccine-induced herd immunity remains the best hope for putting a stop to the pandemic. However, vaccination reluctance for COVID-19 remains a significant issue. Aim: This study aimed to explore the correlation between COVID-19 phobia, intolerance of uncertainty, conspiracy mentality and vaccine hesitancy among Assiut University students. Subjects and method: Design: A correlational descriptive research design was used. Setting: this study conducted in six randomly selected faculties at Assiut University. Subjects: A convenient sample of 1300 male and female students from the selected faculties. Tools: Socio-demographic data, COVID-19 phobia scale, conspiracy mentality questionnaire, intolerance of uncertainty scale and vaccine conspiracy beliefs scale. The results: The participant‟s students' mean age was 20.52 ±1.33 years. 80.9% had previously suffered from COVID-19. 73.1% of the students had first degree relatives with COVID-19.The total mean scores of the students regarding COVID-19 Phobia and intolerance of uncertainty scales were (50.30 ±13.31 and 28.67 ± 9.35) respectively, whereas the mean scores of the conspiracy mentality and vaccine conspiracy beliefs among the students were (29.70. ± 13.12 and 25.98 ± 9.48) respectively. Conclusion: The current study revealed a strong correlation between COVID-19, intolerance of uncertainty, vaccine conspiracy and conspiracy mentality among studied students and moderate relation between COVID-19, intolerance of uncertainty, vaccine conspiracy and conspiracy mentality and socio-demographic data. Recommendations: Use a different way of social media to explain the importance of vaccines e.g. posters, brochures, gestures, educational videos and innovative technologies such as interactive mobile apps.