This study shed the light on the effect of light intensity on some of the dependent variables, such as blood oxygen saturation (SPO2%), heart pulse rate (P.R), arterial blood pressure (systolic (SBP), diastolic (DBP)), and tympanic temperature (T) of nurses, in their shift work.The sample consists of 207 nurses of both genders (104 female, 103 male), with mean age 29 years, and the mean duration of employment 6 years, were randomly chosen as a sample to fulfill the aimmeant. This sample was taken fromfour hospitals in Nablus city. The values of light intensity in all hospital ranged from220 Lux to 1000 Lux, at the day shift, and from500 Lux to 1700 Lux, at the night shift.Anumber of measurements concerning the blood oxygen saturation, heart pulse rate, arterial blood pressure (systolic and diastolic), and tympanic temperature at different light intensities were taken for the selected sample before and an after exposure to light. Strong positive correlation (Pearson Correlation Coefficient) with light intensity was found for allmeasured variables. The statistical result for the dependent variables (SPO2%, P.R, SBP, DBP, T) showed that Pearson correlation coefficient (R) between light intensity and the dependent variables are approximately equal to one, and the Probabilities (P) are < 0.05.