Emotional display is the management and proper expression of correct emotions consistent with organizational and profession rules. One of the factors affecting the occupational performance is the skills of the managers in control and effective use of excitement. The present study was conducted to determine the relationship between nursing managers' emotional display and the performance of nursing staff. The study population consisted of all managers and nursing staff of Shariati Hospital, Tehran in 2015 who were selected using census method. The instruments were Dindorf et al. emotional display questionnaire and Paterson's job performance questionnaire whose validity and reliability were confirmed. Data were analyzed with Spearman correlation Coefficient, independent t-test, and ANOVA using SPSS software. "Real-emotion display" of nursing managers had a significant correlation with nursing staff performance (P=0.02, r=0.203). But "superficial and deep display of emotions" of the managers did not. There were no significant correlations between emotional display with age and work experience in managers and between job performance with marital status, gender, and age and work experience in nursing staff (P>0.05). The results showed that design and implementation of training courses about emotional display are necessary in managers in order to improve the job performance of nursing staff.