Background: The induction of anaesthesia is associated with risk of hypotension as anaesthetic agents have myocardial depressant and vasodilatory effects. These are more prevalent in patients with dehydration and an impaired compensatory response. The ‘Collapsibility Index’ of subclavian vein diameter (DSCV-CI) can predict general anesthesia-induced hypotension in deep inspiration. Our study aimed to assess the efficacy of pre-anaesthetic SCV collapsibility in supine and passive leg raising (PLR) to predict hypotension following induction of general anesthesia. Methods: Seventy-four patients belonging to the American Society of Anesthesiologists’ physical status I and II in the age group 18-50 years of either gender scheduled to undergo elective surgeries under general anesthesia (GA) were selected for this study. An average of three ultrasonographic measurements of the subclavian vein (SCV) diameter in supine and passive leg raising (PLR) were taken. The maximum value of SCV diameter was recorded as [DSCVmax]Supine and the minimum as [DSCVmin]Supine in the supine position, and [DSCVmax]PLR and [DSCVmin]PLR during PLR respectively. The collapsibility index of SCV was further calculated from these values. Receiver operating characteristic curve (ROC) analysis, logistic regression, and p-value were used to project the use of DSCV and other parameters in predicting post-induction hypotension. Results: ΔDSCV had a significant difference in patients who developed post-induction hypotension and those who did not develop hypotension. The area under the curve for ΔDSCV in predicting hypotension after general anesthesia induction was 0.7 (95% CI: 0.53–0.87), while DSCV and CI were less than 0.7. Conclusion: ΔDSCV has better predictive value for hypotension that occurs following induction of general anesthesia.