Background: The low-dose ropivacaine provides differential spinal block to reduce adverse hemodynamic effects in elderly patients. Addition of intrathecal fentanyl with ropivacaine may enhance analgesia and early postoperative mobility. The present study was performed to evaluate the efficacy of intrathecal ropivacaine alone and in combination with fentanyl in transurethral resection operation. Methods: Sixty male patients aged >50 years of ASA I-III scheduled for elective transurethral resection were included in a prospective, randomized, double-blinded study and they were divided in two groups of 30 each. Group A (n = 30) received intrathecal injection of ropivacaine 2 ml (0.75%) and Group B (n = 30) ropivacaine 1.8 ml (0.75%) with fentanyl 10 μg. The characteristics of onset and regression of sensory and motor blockade, hemodynamic stability, and side effects were observed. Student′s t test (for parametric data) and Mann-Whitney U test (for non-parametric data) were used for statistical analyses. Results: There were no significant differences between the two groups for patient demographic data, intraoperative hemodynamic parameters, side effects, and satisfaction to patients and surgeon. The highest level of sensory block was at T10 in group A and T9 in group B (P = 0.001). Duration of motor block was longer in group B being 210.51 ± 61.25 min than in group A being 286.25 ± 55.65 min (P < 0.001). Conclusion: The addition of fentanyl to ropivacaine may offer the advantage of shorter duration of complete motor block, hemodynamic stability, and without any increase in the frequency of major side effects.