Abstract : Nurses working at ICUs are at risk of developing mental health disorders such as anxiety and depression due to the highly demanding nature of their work and the working environment. Indeed, these disorders may negatively influence the health status of nurses and might decrease the level of nurses’ professional performance. Purpose: To investigate the effect of anxiety and depression on the performance of nurses working in intensive care units in Jordan. A non-experimental descriptive cross-sectional design was used for this study. A validated self-reported questionnaire; the Hospital Anxiety and Depression Scale and the Six-Dimensional Scale of Nursing Performance were used among 375 nurses. Nurses working in ICUs were picked from two private and two governmental hospitals in Jordan. Jordanian nurses working in ICUs had a mild level of anxiety and depression with a mean score of (8.25 ± 3.74; 8.61 ±3 .67, respectively). The lower levels of anxiety, the lower levels of depression predicted higher quality and frequency in performing nursing care. The higher level of education predicted higher quality of performing activities while the higher years of experience and nurse working in governmental hospitals predicted a higher frequency of performing nursing activities. Anxiety and depression faced by ICU nurses in Jordan negatively affected their performance and therefore the outcome of the patient health status. Therefore, assessing factors causing anxiety and depression among nurses is crucial. Future research may implement strategies to decrease anxiety and depression and examine the effect of these strategies on the performance of the nurses