Objective: To determine the difference in the sleep quality and work performance of nurses between one shift duty, two shifts duty, and three shifts duty in intensive care units at a government hospital in the Kingdom of Bahrain. Methods: This cross-sectional study was conducted at a government hospital of Bahrain from February to April 2021. A total of 200 nurses worked for at least one year in an intensive care units were eligible for the study. A questionnaire was administered online to collect data. The Pittsburgh Sleep Quality Index (PSQI) was used to measure sleep quality while Nurse Work Function Questionnaire (NWFQ) was used to measure work performance. Results: There were 145 (72.5%) females and 55 (27.5%) males with a mean age of 38.2 ± 8.2 years. Most of the nurses were staff nurses 188 (94%), and shift workers 178 (89%). The mean PSQI of nurses who work only one shift reported normal sleep quality of 1.3 ± 1.0 where those who work two shifts had poorer sleep quality measured 9.2 ± 0.8 and nurses who work three shifts had reported even worse sleep quality with a statistically significant difference 15.6 ± 1.8 (p-value <0.0001). Moreover, the more variety of shifts the critical care nurses work, the more impaired their performance was (p-value <0.001). Conclusion: The more shift work schedules the nurse works, the worse is the reported sleep quality and work performance.