Context: SAB is safe and effective technique for TURP, offers advantage of easy identification of TURP syndrome, bladder perforations but, associated with hemodynamic changes like hypotension and bradycardia in geriatric patients with coexisting cardiac and respiratory diseases. Hence the study had been undertaken with low dose bupivacaine in combination with tramadol. Aims: To evaluate the efficacy of very low dose bupivacaine with tramadol as an alternative to conventional dose of bupivacaine in TURP surgeries. Settings and Design: Randomised double blind prospective study. Methods and Material: 64 patients scheduled for TURP surgeries, aged 55-75 years with ASA-PS I and II were recruited and randomly divided into 2 groups. Group I-injection bupivacaine 0.5 ml (2.5 mg)+ preservative free tramadol 1 ml (50 mg) diluted with 0.5 ml NS intrathecally. Group II-injection bupivacaine 2 ml (10 mg) intrathecally. Statistical analysis used: Data analysis: SPSS 22 version software; Categorical data: frequencies and proportions; Continuous data:mean+ SD. Tests of significance: Chisquare test and independent t test. p value < 0.05: statistically significant. Results: Attainment of sensory blockade in group I was slow ie., 8.44 ± 2.35 min compared to that in group II ie., 6.53 ± 1.65 min and the two segment regression is faster in group I ie., 65.38 ± 20.52 min compared that of group II ie., 86.78 ± 36.88 min which were statistically significant. The time for rescue analgesia was significantly higher in group I ie., 312.56 ± 137.42 min compared to group II ie., 256.97 ± 130.46 min. The degree of motor blockade was less in group I. There were no significant changes in heart rate and SpO2, but the fall in MAP in group II was significant compared to that in group I. Conclusions: 50 mg preservative free Tramadol added to intrathecal bupivacaine 2.5 mg offers adequate anaesthesia, stable hemodynamics, early ambulation and prolongs analgesia.