Introduction: Death anxiety (DA) is one of the stresses experienced by intensive care unit (ICU) nurses on a daily basis. Failure to pay attention to DA causes psychological problems and job dissatisfaction for nurses and failure to receive proper and adequate care for patients. Aim of the study: To determine the effect of guided imagery (GI) on DA among ICU nurses. Material and methods: This quasi-experimental (pre-test-post-test) study was conducted on 50 ICU nurses in one educational hospital of Zabol University of Medical Sciences in south east Iran from 10 January to 10 June 2020. The participants were selected using the convenience sampling method then divided into two groups, intervention (n = 25) and control (n = 25). In the intervention group, participants received GI using theory education by lecture, pamphlet, booklet, and practice. In the control group participants received no specific intervention. In both groups DA was assessed by the researcher using the Templer DA scale at the start of study, and one month after intervention. SPSS ver. 23 was used for data analysis. Results: The results showed in the intervention group after one months of GI mean score of DA significantly decreased from 53.28 to 43.48 (p = 0.01). In the control group there was no significant difference before and after intervention (p > 0.05). Conclusions: Based on the results of the present study GI can be used as an effective method to decrease the DA and improve the mental health of nurses in ICU.