Nursing work efforts are important in providing sound healthcare services, especially in the intensive care units (ICU). Complications and adverse events are more liable to occur among patients in the ICU and these patients require more attention and nursing care. Most of the research in this field is mainly focused on the effect of staffing and its correlation to patient safety and satisfaction. Previous studies also showed that reduced nursing staffing was significantly associated with the development of pneumonia in ICU patients who needed more nursing requirements. An increase in nursing workload is also significantly associated with an increased incidence rate of nosocomial infections. The association between nursing workload in ICU patients and increased incidence rates of mortality is also supported by previous studies. The nurse-to-patient ratio has been previously used to evaluate patient safety correlation with the nursing workload as reported by previous reports. However, previous research shows that the nursing workload is a more complex correlation and can not be determined by a simple ratio as the nurse-to-patient one. Evidence shows that many adverse events may occur with patients in the ICU secondary to reduced nursing care such as increased mortality, length of hospital stay, and catching in-hospital infections. In the current study, we aim to review the outcomes from previous investigations to further emphasize the effect of nursing workload on ICU patient outcomes and safety.