Reaction time has been defined as the time interval between the application of a stimulus and the response by the subject. Various factors affect reaction time like handedness, age and gender of the person, BMI, type of receptor system involved. It is well known that there exist relationship among Visual Reaction Time, age and BMI. The degree of correlation among these variables is found to be higher. In this paper we develop a multivariate regression line in the form of z = ax +by +c, where x, y are two independent variable (x=age, y=BMI) and z is the measure of visual reaction time.