Background: The COVID-19 outbreak has made it difficult to assess students using standard approaches. Teachers are compelled to acquire new methods of evaluation and employ alternative forms of performance assessment to prevent the virus from spreading amongst their students. Some educational communities believe that traditional assessment methods are the more effective, while others have different thoughts. Aim: the study aims to compare between nursing students' satisfaction and achievement of online and paper-based exam during COVID 19 outbreak. Research questions: is there a difference between nursing students' satisfaction of online and paper-based exam? Is there a difference between the nursing students' achievement of online and paper-based exam? Design: comparative descriptive research design was used to conduct this study. Setting: This study was conducted at Nursing Education Department and Community health Nursing Department, Faculty of Nursing, Alexandria University. Sample: A convenience sampling of 200 nursing students comprised the study subjects. Results: Statistically significant differences regarding students' satisfaction and achievement were found in the favor of paper-based exam. Conclusion: Despite students' overwhelming preference for paper-based exam, online exam can be a viable alternative to traditional evaluation for students' knowledge assessment if special attention is paid to its composition. Recommendation: All nursing curricula should be revised to include nursing learning outcomes and competencies that match the new era of online teaching and evaluation. Therefore, the current study recommends a condensed training for the students to use the online exams and online assessment.