Objectives Cognitive functions such as reaction time undergo change with aging. Given the importance of preparation in response to reaction time in various life situations, this study aimed to examine the effect of various foreperiods (0.5, 1.5, 2.5, and 3.5 s), and handedness at the time of simple and choice auditory reaction time. 
Methods & Materials The current research followed a quasi-experimental methodology and was carried out using a self-made software. The study population comprised all old people living in Ahvaz City. Of them, 30 people were selected through purposive sampling method and allocated into two groups of right- and left-handed people. Each individual was randomly tested for simple and selective reaction with randomly chosen foreperiods. 
Results The findings demonstrated a significant difference (P<0.05) between the different periods, and between simple and choice reaction time. It means that short (0.5 and 1.5 s) foreperiods result in the increase of reaction time and that left-handed individuals are associated with shorter reaction times compared with their right-handed counterparts.
Conclusion Since cognitive processing occurs slower in the elderly, it is recommended that foreperiods with very short durations be avoided when preparing elders for different motor skills. In addition, the dominance of the right hemisphere, which contains higher numbers of neurons, among the left-handed might lead them to possess lower reaction times compared with right-handed individuals.