Background: Most hospitals have restricted visitation time in intensive care units (ICUs) for various reasons. Given the advantages of family presence and positive effect of emotional touching, talking and smiling on nervous system stimulation and vital signs of the patients.Objectives: The present study aimed to determine the effect of increased visitation time on physiological indices of the patients hospitalized in ICUs.Materials and Methods: This clinical trial study was conducted in the ICUs of Vail-e-Asr hospital in Arak city, Iran. A total of 60 subjects were randomly assigned to the intervention and control groups with visitation time for 10 minutes 3 times a day and 10 minutes once a day, respectively. Then, the patients’ physiological indices were measured before, during, and 10 and 30 minutes after the hospital visiting hours. Data were analyzed using SPSS version 20.Results: Findings showed no statistically significant differences among mean values of all physiological indices in measurement stages before, during, and 10 and 30 minutes after the visitation times in the control group (P>0.05). While, in the intervention group, systolic blood pressure (SBP) measurements at 9 (previous mean: 126.9, 30 minutes later: 111.9), 12: 00 PM (previous mean: 126.9, 30 minutes later: 114.9), and 3: 00 PM (previous mean: 125.2, 30 minutes later: 105.8), diastolic blood pressure (DBP) measurements at 9: 00 AM (previous mean: 87.4, 30 minutes later: 83.2), 12: 00 PM (previous mean: 86.6, 30 minutes later: 81.7), and 3: 00 PM (previous mean: 87.1, 30 minutes later: 85.0), heart rate (HR) measurements at 9: 00 AM (previous mean: 90, 30 minutes later: 78.4), 12: 00 PM (previous mean: 89.8, 30 minutes later: 78.6), and 3: 00 PM (previous mean: 89.3, 30 minutes later: 78.3), repertory rate (RR) measurements at 9: 00 AM (previous mean: 20.9, 30 minutes later: 15.0), 12: 00 PM (previous mean: 20.6, 30 minutes later: 15.4), and 3: 00 PM (previous mean: 21.0, 30 minutes later: 15.9) showed statistically significant differences (P<0.05). However, no statistically significant differences were observed among Oxygen saturation (OS) measurements at 9: 00 AM, 12: 00 PM and 3: 00 PM in this latter group as well (P>0.05).Conclusions: Increasing visitation time leads to reduced physiological indices’ mean values. Hence, it is recommended to extend hospital visiting times in order to improve the condition of patients admitted to ICU.