Background: Nonverbal communication plays a vital role in determining the success or failure of people in their ordinary life and professional careers. In a classroom, successful educator- student communication has a critical effect on teaching proficiency and student learning. Aim of the study: to assess the effect of body language among assistants teaching staff on students' achievement. Subjects and Methods: Research design: Cross –sectional descriptive research design .Setting: the Faculty of Nursing, Zagazig University. Subjects: included a simple random composed of 330 students. Tools of data collection: Three tools were used for data collection: questionnaire to collect data about socio-demographic characteristics, nonverbal communication scale, and a student achievement scale. Results: present study showed that more than half of the studied sample reported that body language skills were inadequate among staff and about half of the studied sample had low achievement score. There was a highly significant positive correlation between staff's body language and students 'achievement scores as most of the students who reported adequate staff's nonverbal communication skills had moderate and high achievement scores. Conclusion: The staff's body language skills had an effect on students' achievement. Recommendations: Holding seminars & workshops to improve nonverbal communication skills of the teaching staff.